一些图论、网络流入门题总结、汇总

系统管理员 2022-09-24 05:15 165阅读 0赞

**最短路问题**  
此类问题类型不多，变形较少

POJ 2449 Remmarguts' Date(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2449][http_acm.pku.edu.cn_JudgeOnline_problem_id_2449]  
题意：经典问题：K短路  
解法：dijkstra+A\*(rec)，方法很多  
相关：[http://acm.pku.edu.cn/JudgeOnline/showcontest?contest\_id=1144][http_acm.pku.edu.cn_JudgeOnline_showcontest_contest_id_1144]  
该题亦放在搜索推荐题中  
  
  
POJ 3013 - Big Christmas Tree(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3013][http_acm.pku.edu.cn_JudgeOnline_problem_id_3013]  
题意：最简单最短路，但此题要过，需要较好的程序速度和，还要注意精度  
解法：Dijkstra

POJ 3463 - Sightseeing(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3463][http_acm.pku.edu.cn_JudgeOnline_problem_id_3463]  
题意：最短路和比最短路大1的路的数量  
解法：需要真正理解dijkstra

POJ 3613 - Cow Relays(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3613][http_acm.pku.edu.cn_JudgeOnline_problem_id_3613]  
题意：求经过N条边的最短路  
解法：floyd + 倍增，贪心

POJ 3621 - Sightseeing Cows(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3621][http_acm.pku.edu.cn_JudgeOnline_problem_id_3621]  
题意：求一个环路，欢乐值 / 总路径最大  
解法：参数搜索 + 最短路(ms 原始的bellman tle, 用spfa才过)  
  
  
POJ 3635 - full tank?(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3635][http_acm.pku.edu.cn_JudgeOnline_problem_id_3635]  
题意：最短路变形  
解法：广搜  
相关：[http://hi.baidu.com/hnu\_reason/blog/item/086e3dccfc8cb21600e9286b.html][http_hi.baidu.com_hnu_reason_blog_item_086e3dccfc8cb21600e9286b.html]

**生成树问题**  
基本的生成树就不放上来了

POJ 1639 - Picnic Planning(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1639][http_acm.pku.edu.cn_JudgeOnline_problem_id_1639]  
题意：顶点度数有限制的最小生成树  
解法：贪心 + prim/kruskal

POJ 1679 - The Unique MST(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1679][http_acm.pku.edu.cn_JudgeOnline_problem_id_1679]  
题意：判断MST是否唯一  
解法：prim就行，不过还是易错的题

POJ 2728 - Desert King(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2728][http_acm.pku.edu.cn_JudgeOnline_problem_id_2728]  
题意：所谓最优比率生成树  
解法：参数搜索 + prim

POJ 3164 - Command Network(难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3164][http_acm.pku.edu.cn_JudgeOnline_problem_id_3164]  
题意：最小树形图  
解法：刘朱算法，这个考到的可能性比较小吧？

POJ 3522 - Slim Span(基础)[  
http://acm.pku.edu.cn/JudgeOnline/problem?id=3522][http_acm.pku.edu.cn_JudgeOnline_problem_id_3522]  
题意：求一颗生成树，让最大边最小边差值最小  
解法：kruskal活用

**连通性，度数，拓扑问题**  
此类问题主要牵扯到DFS，缩点等技巧

POJ 1236 - Network of Schools(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1236][http_acm.pku.edu.cn_JudgeOnline_problem_id_1236]  
题意：问添加多少边可成为完全连通图  
解法：缩点，看度数

POJ 1659 - Frogs' Neighborhood(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1659][http_acm.pku.edu.cn_JudgeOnline_problem_id_1659]  
题意：根据度序列构造图  
解法：贪心，详细证明参见havel定理

POJ 2553 - The Bottom of a Graph(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2553][http_acm.pku.edu.cn_JudgeOnline_problem_id_2553]  
POJ 2186 - Popular Cows(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2186][http_acm.pku.edu.cn_JudgeOnline_problem_id_2186]  
题意：强连通分量缩点图出度为0的点

POJ 2762 - Going from u to v or from v to u?(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2762][http_acm.pku.edu.cn_JudgeOnline_problem_id_2762]  
题意：单向连通图判定  
解法：缩点 + dp找最长链

POJ 2914 - Minimum Cut(难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2914][http_acm.pku.edu.cn_JudgeOnline_problem_id_2914]  
题意：无向图最小割  
解法：Stoer-Wagner算法，用网络流加枚举判定会挂

POJ 2942 - Knights of the Round Table(难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2942][http_acm.pku.edu.cn_JudgeOnline_problem_id_2942]  
题意：求双联通分量(或称块)中是否含奇圈  
解法：求出双连通分量后做黑白染色进行二分图图判定  
相关：[http://hi.baidu.com/zfy0701/blog/item/57ada7ed104ce9d2b31cb104.html][http_hi.baidu.com_zfy0701_blog_item_57ada7ed104ce9d2b31cb104.html]

POJ 3177 - Redundant Paths(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3177][http_acm.pku.edu.cn_JudgeOnline_problem_id_3177]

POJ 3352 - Road Construction(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3352][http_acm.pku.edu.cn_JudgeOnline_problem_id_3352]  
题意：添加多少条边可成为双向连通图  
解法：把割边分开的不同分量缩点构树，看入度  
建议对比下1236，有向图添加多少条边变成强连通图

POJ 3249 - Test for Job(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3249][http_acm.pku.edu.cn_JudgeOnline_problem_id_3249]  
解法：bfs / dfs + dp

POJ 3592 - Instantaneous Transference(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3592][http_acm.pku.edu.cn_JudgeOnline_problem_id_3592]  
解法：缩点，最长路，少人做的水题，注意细节

POJ 3687 - Labeling Balls(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3687][http_acm.pku.edu.cn_JudgeOnline_problem_id_3687]  
解法：拓扑排序

POJ 3694 - Network(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3694][http_acm.pku.edu.cn_JudgeOnline_problem_id_3694]  
解法：双连通分量+并查集

**2-SAT问题**  
此类问题理解合取式的含义就不难

POJ 2723 - Get Luffy Out(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2723][http_acm.pku.edu.cn_JudgeOnline_problem_id_2723]  
POJ 2749 - Building roads(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2749][http_acm.pku.edu.cn_JudgeOnline_problem_id_2749]  
解法：二分 + 2-SAT判定

POJ 3207 - Ikki's Story IV - Panda's Trick(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3207][http_acm.pku.edu.cn_JudgeOnline_problem_id_3207][  
][Link 1]解法：简单的2-sat，不过其他方法更快

POJ 3648- Wedding(中等)[  
http://acm.pku.edu.cn/JudgeOnline/problem?id=3648][Link 1]  
解法：用2-sat做会比较有意思，但是暴搜照样0ms

POJ 3678 - Katu Puzzle(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3678][http_acm.pku.edu.cn_JudgeOnline_problem_id_3678]  
解法：直接按合取式构图验证就行了

POJ 3683 - Priest John's Busiest Day(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3683][http_acm.pku.edu.cn_JudgeOnline_problem_id_3683]  
解法：n^2枚举点之间的相容性构图，求解2-SAT

**最大流问题**  
变形很多，最小割最大流定理的理解是关键

POJ 1149 - PIGS(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1149][http_acm.pku.edu.cn_JudgeOnline_problem_id_1149]  
绝对经典的构图题

POJ 1273 - Drainage Ditches(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1273][http_acm.pku.edu.cn_JudgeOnline_problem_id_1273]  
最大流入门

POJ 1459 - Power Network(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1459][http_acm.pku.edu.cn_JudgeOnline_problem_id_1459]  
基本构图

POJ 1637 - Sightseeing tour(Crazy)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1637][http_acm.pku.edu.cn_JudgeOnline_problem_id_1637]  
题意：求混合图的欧拉迹是否存在  
解法：无向边任意定向，构图，详建黑书P324

POJ 1815 - Friendship(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1815][http_acm.pku.edu.cn_JudgeOnline_problem_id_1815]  
题意：求最小点割  
解法：拆点转换为边割  
相关：[http://hi.baidu.com/zfy0701/blog/item/a521f230b06dea9fa9018e0e.html][http_hi.baidu.com_zfy0701_blog_item_a521f230b06dea9fa9018e0e.html]

POJ 1966 - Cable TV Network(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1966][http_acm.pku.edu.cn_JudgeOnline_problem_id_1966]  
题意：去掉多少点让图不连通  
解法：任定一源点，枚举汇点求点割集(转换到求边割)，求其中最小的点割  
  
  
POJ 2112 - Optimal Milking(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2112][http_acm.pku.edu.cn_JudgeOnline_problem_id_2112]  
二分枚举，最大流

POJ 2391 - Ombrophobic Bovines(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2391][http_acm.pku.edu.cn_JudgeOnline_problem_id_2391]  
题意：floyd, 拆点，二分枚举  
相关：[http://hi.baidu.com/zfy0701/blog/item/3e0006c4f73f0eaf8226acff.html][http_hi.baidu.com_zfy0701_blog_item_3e0006c4f73f0eaf8226acff.html]

POJ 2396 - Budget(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2396][http_acm.pku.edu.cn_JudgeOnline_problem_id_2396]  
题意：有源汇的上下界可行流  
解法：用矩阵-网络流模型构图，然后拆边  
相关：[http://hi.baidu.com/zfy0701/blog/item/6449d82a64e15e3e5343c1ba.html][http_hi.baidu.com_zfy0701_blog_item_6449d82a64e15e3e5343c1ba.html]  
，最小割模型在竞赛中的应用

POJ 2455 - Secret Milking Machine(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2455][http_acm.pku.edu.cn_JudgeOnline_problem_id_2455]  
二分枚举，一般来说需要写对边容量的更新操作而不是每次全部重新构图

POJ 2699 - The Maximum Number of Strong Kings(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2699][http_acm.pku.edu.cn_JudgeOnline_problem_id_2699]  
解法：枚举人数 + 最大流(感谢xpcnq\_71大牛的建图的提示)

POJ 2987 - Firing(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2987][http_acm.pku.edu.cn_JudgeOnline_problem_id_2987]  
题意：最大权闭包  
解法：先边权放大，第一问总量-最大流，第二问求最小割  
相关：[http://wywcgs.spaces.live.com/blog/cns!4D861A02A3382142!1109.entry?&\_c02\_owner=1][http_wywcgs.spaces.live.com_blog_cns_4D861A02A3382142_1109.entry_c02_owner_1]  
Profit(中等)  
[http://www.vijos.cn/Problem\_Show.asp?id=1352][http_www.vijos.cn_Problem_Show.asp_id_1352]  
最大权闭包图的特殊情况  
ZOJ 2071 - Technology Trader 也是此类型，懒了没做  
[http://acm.zju.edu.cn/show\_problem.php?pid=2071][http_acm.zju.edu.cn_show_problem.php_pid_2071]

POJ 3084 - Panic Room(中等，好题)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3084][http_acm.pku.edu.cn_JudgeOnline_problem_id_3084]  
题意：略  
解法：根据最小割建模

POJ 3155 - Hard Life(很挑战一题)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3155][http_acm.pku.edu.cn_JudgeOnline_problem_id_3155]  
题意：最大密度子图  
解法：参数搜索 + 最大权闭合图，A.V.Goldberg的论文(nb解法)  
最小割模型在信息学竞赛中的应用 一文中也有讲

POJ 3189 - Steady Cow Assignment(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3189][http_acm.pku.edu.cn_JudgeOnline_problem_id_3189]  
题意：寻找最小的区间完成匹配  
解法：这题充分说明SAP的强大，纯暴力可过。更好的方法是在枚举区间的过程中不断删边和加边继续网络流过程

POJ 3204 - Ikki's Story I - Road Reconstruction(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3204][http_acm.pku.edu.cn_JudgeOnline_problem_id_3204]

ZOJ 2532 - Internship(基础)  
[http://acm.zju.edu.cn/show\_problem.php?pid=2532][http_acm.zju.edu.cn_show_problem.php_pid_2532]  
题意：确定边是否是某个割中的边  
解法：两边dfs求割, 或暴力枚举(需要写取消某条增广路的操作(但数据弱，也许不取消也能混过))

POJ 3308 - Paratroopers(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3308][http_acm.pku.edu.cn_JudgeOnline_problem_id_3308]  
POJ 2125 - Destroying The Graph(难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2125][http_acm.pku.edu.cn_JudgeOnline_problem_id_2125]  
题意：最小点权覆盖  
  
  
POJ 3469 - Dual Core CPU(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3469][http_acm.pku.edu.cn_JudgeOnline_problem_id_3469]  
题意：最小割

POJ 3498 - March of the Penguins(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3498][http_acm.pku.edu.cn_JudgeOnline_problem_id_3498]  
题意：满足点容量限制的网络流  
解法：拆点把点容量转换为边容量，枚举汇点

ZOJ 2587 - Unique Attack(较难)  
[http://acm.zju.edu.cn/show\_problem.php?pid=2587][http_acm.zju.edu.cn_show_problem.php_pid_2587]  
题意：确定最小割是否是唯一的  
解法：得理解dfs求最小割算法的本质  
  
  
SPOJ 839 - Optimal Marks(难)  
[http://www.spoj.pl/problems/OPTM/][http_www.spoj.pl_problems_OPTM]  
题意：略  
解法：很经典哦，见amber的集训队论文，根据标号的每一位求最小割

SGU 326 - Perspective(中等)  
[http://acm.sgu.ru/problem.php?contest=0&problem=326][http_acm.sgu.ru_problem.php_contest_0_problem_326]  
比较经典的构图法

费用流问题  
可以KM解的就不放在这里，另外，感觉除非很特殊的图，一般用连续增广路的算法就够了

POJ 2175 - Evacuation Plan(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2175][http_acm.pku.edu.cn_JudgeOnline_problem_id_2175]  
题意：判断是否给定解是最优解，比较阴的一题  
解法：根据给出的计划构造流，然后消且只消一次负圈

POJ 3422 - Kaka's Matrix Travels(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3422][http_acm.pku.edu.cn_JudgeOnline_problem_id_3422]  
题意：略  
解法：拆点

POJ 3680 - Intervals(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3680][http_acm.pku.edu.cn_JudgeOnline_problem_id_3680]  
题意：略，这题还是蛮经典  
解法：discuss中比较详细

SPOJ 371 - Boxes(简单)  
[http://www.spoj.pl/problems/BOXES/][http_www.spoj.pl_problems_BOXES]  
题意：略  
解法：费用流，但似乎有比网络流更好的做法

SGU 185 - Two shortest(中等)  
[http://acm.sgu.ru/problem.php?contest=0&problem=185][http_acm.sgu.ru_problem.php_contest_0_problem_185]  
题意：求两条不想交的最短路径  
解法：费用流，也可以最短路 + 最大流。

**匹配问题**  
正确理解KM算法是很重要的

这里我还要说几句：最正确解最小权匹配的办法是用一个很大的数-当前边权值，而不是直接对边权取反(这样只能处理左右点相等的完全二分图，即K(n, n)

以上有可能还是说的有点问题，以后补充

POJ 1486 - Sorting Slides(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1486][http_acm.pku.edu.cn_JudgeOnline_problem_id_1486]  
题意：二分图的必须边  
解法：需正真理解最大匹配算法，详见[http://hi.baidu.com/kevin0602/blog/item/1d5be63b5bec9bec14cecb44.html][http_hi.baidu.com_kevin0602_blog_item_1d5be63b5bec9bec14cecb44.html]

POJ 1904 - King's Quest(中等，好题)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1904][http_acm.pku.edu.cn_JudgeOnline_problem_id_1904]  
题意：求二分图所有可能的匹配边  
解法：虽然最终不是用匹配算法，但需要理解匹配的思想转换成强连通分量问题。

POJ 2060 -Taxi Cab Scheme(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2060][http_acm.pku.edu.cn_JudgeOnline_problem_id_2060]  
题意：最小路径覆盖

POJ 2594 -Treasure Exploration(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2594][http_acm.pku.edu.cn_JudgeOnline_problem_id_2594]  
题意：可相交最小路径覆盖  
解法：先传递闭包转化下  
  
  
POJ 3041 - Asteroids(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3041][http_acm.pku.edu.cn_JudgeOnline_problem_id_3041]  
POJ 2226 - Muddy Fields(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2226][http_acm.pku.edu.cn_JudgeOnline_problem_id_2226]  
题意：行列的覆盖  
解法：最小点集覆盖 = 最大匹配

POJ 2195 - Going Home(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2195][http_acm.pku.edu.cn_JudgeOnline_problem_id_2195]  
题意：最小权值匹配  
解法：KM算法

POJ 2400 - Supervisor, Supervisee(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2400][http_acm.pku.edu.cn_JudgeOnline_problem_id_2400]  
题意：输出所有最小权匹配  
解法：KM, 然后回溯解，汗，输入的两个矩阵居然是反过来的

POJ 2516 -Minimum Cost(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2516][http_acm.pku.edu.cn_JudgeOnline_problem_id_2516]  
题意：最小权值匹配或最小费用流  
解法：拆点 + KM算法(只有正确的才能过)，费用流(ms错的可能也能过)

POJ 3686 - The Windy's(较难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=3686][http_acm.pku.edu.cn_JudgeOnline_problem_id_3686]  
题意：最小权值匹配  
解法：拆点,然后尽管用KM算法去水吧，数据其实弱得不得了 O(50 \* 50 \* 2500) -> 16ms  
相关：[http://hi.baidu.com/kevin0602/blog/item/2829dc01d7143b087bec2c97.html][http_hi.baidu.com_kevin0602_blog_item_2829dc01d7143b087bec2c97.html]

SPOJ 412 - K-path cover(较难)  
[https://www.spoj.pl/problems/COVER/][https_www.spoj.pl_problems_COVER]  
题意：略  
解法：很牛叉的一道匹配  
相关：[http://hi.baidu.com/roba/blog/item/c842fdfac10d24dcb48f31d7.html][http_hi.baidu.com_roba_blog_item_c842fdfac10d24dcb48f31d7.html]

SGU 206. Roads(较难)  
[http://acm.sgu.ru/problem.php?contest=0&problem=206][http_acm.sgu.ru_problem.php_contest_0_problem_206]  
解法：经典题目，也可以使用spoj 412那题的优化

**NP问题**  
一般是搜索或dp解的

POJ 1419 - Graph Coloring(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1419][http_acm.pku.edu.cn_JudgeOnline_problem_id_1419]  
题意：图的着色  
解法：搜索，可惜题目的数据真是太弱了

POJ 2989 - All Friends(难)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=2989][http_acm.pku.edu.cn_JudgeOnline_problem_id_2989]  
题意：极大团数量  
解法：开始狂tle, 后来找了论文：Finding All Cliques of an Undirected Graph（Coen Bron & Joep Kerboscht）

ZOJ 1492 - Maximum Clique(基础)  
[http://acm.zju.edu.cn/show\_problem.php?pid=1492][http_acm.zju.edu.cn_show_problem.php_pid_1492]  
题意：图的最大团  
解法：搜索，如果要求速度，可参考下相应论文

其他  
不能成大类的

POJ 1470 - Closest Common Ancestors(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1470][http_acm.pku.edu.cn_JudgeOnline_problem_id_1470]  
题意：LCA问题  
解法：tarjan或RMQ，另外输入很恶心

POJ 1985 - Cow Marathon(基础)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1985][http_acm.pku.edu.cn_JudgeOnline_problem_id_1985]  
题意：树上的最长路径  
解法：dp

POJ 1986 - Distance Queries(中等)  
[http://acm.pku.edu.cn/JudgeOnline/problem?id=1986][http_acm.pku.edu.cn_JudgeOnline_problem_id_1986]  
题意：LCA  
解法：tarjan或RMQ

HOJ 11192 - Justice League(有趣的图论)  
[http://acm.hnu.cn:8080/online/?action=problem&type=show&id=11192&courseid=99][http_acm.hnu.cn_8080_online_action_problem_type_show_id_11192_courseid_99]

HOJ 11277 - New Island(有趣的图论)  
[http://acm.hnu.cn:8080/online/?action=problem&type=show&id=11277&courseid=109][http_acm.hnu.cn_8080_online_action_problem_type_show_id_11277_courseid_109]

人一我百！人十我万！永不放弃~~~怀着自信的心，去追逐梦想

[http_acm.pku.edu.cn_JudgeOnline_problem_id_2449]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2449
[http_acm.pku.edu.cn_JudgeOnline_showcontest_contest_id_1144]: http://acm.pku.edu.cn/JudgeOnline/showcontest?contest_id=1144
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3013]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3013
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3463]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3463
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3613]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3613
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3621]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3621
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3635]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3635
[http_hi.baidu.com_hnu_reason_blog_item_086e3dccfc8cb21600e9286b.html]: http://hi.baidu.com/hnu_reason/blog/item/086e3dccfc8cb21600e9286b.html
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1639]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1639
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1679]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1679
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2728]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2728
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3164]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3164
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3522]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3522
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1236]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1236
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1659]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1659
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2553]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2553
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2186]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2186
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2762]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2762
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2914]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2914
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2942]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2942
[http_hi.baidu.com_zfy0701_blog_item_57ada7ed104ce9d2b31cb104.html]: http://hi.baidu.com/zfy0701/blog/item/57ada7ed104ce9d2b31cb104.html
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3177]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3177
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3352]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3352
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3249]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3249
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3592]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3592
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3687]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3687
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3694]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3694
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2723]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2723
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2749]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2749
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3207]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3207
[Link 1]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3648
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3678]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3678
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3683]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3683
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1149]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1149
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1273]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1273
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1459]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1459
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1637]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1637
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1815]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1815
[http_hi.baidu.com_zfy0701_blog_item_a521f230b06dea9fa9018e0e.html]: http://hi.baidu.com/zfy0701/blog/item/a521f230b06dea9fa9018e0e.html
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1966]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1966
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2112]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2112
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2391]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2391
[http_hi.baidu.com_zfy0701_blog_item_3e0006c4f73f0eaf8226acff.html]: http://hi.baidu.com/zfy0701/blog/item/3e0006c4f73f0eaf8226acff.html
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2396]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2396
[http_hi.baidu.com_zfy0701_blog_item_6449d82a64e15e3e5343c1ba.html]: http://hi.baidu.com/zfy0701/blog/item/6449d82a64e15e3e5343c1ba.html
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2455]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2455
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2699]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2699
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2987]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2987
[http_wywcgs.spaces.live.com_blog_cns_4D861A02A3382142_1109.entry_c02_owner_1]: http://wywcgs.spaces.live.com/blog/cns!4D861A02A3382142!1109.entry?&_c02_owner=1
[http_www.vijos.cn_Problem_Show.asp_id_1352]: http://www.vijos.cn/Problem_Show.asp?id=1352
[http_acm.zju.edu.cn_show_problem.php_pid_2071]: http://acm.zju.edu.cn/show_problem.php?pid=2071
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3084]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3084
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3155]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3155
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3189]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3189
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3204]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3204
[http_acm.zju.edu.cn_show_problem.php_pid_2532]: http://acm.zju.edu.cn/show_problem.php?pid=2532
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3308]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3308
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2125]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2125
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3469]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3469
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3498]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3498
[http_acm.zju.edu.cn_show_problem.php_pid_2587]: http://acm.zju.edu.cn/show_problem.php?pid=2587
[http_www.spoj.pl_problems_OPTM]: http://www.spoj.pl/problems/OPTM/
[http_acm.sgu.ru_problem.php_contest_0_problem_326]: http://acm.sgu.ru/problem.php?contest=0&problem=326
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2175]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2175
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3422]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3422
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3680]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3680
[http_www.spoj.pl_problems_BOXES]: http://www.spoj.pl/problems/BOXES/
[http_acm.sgu.ru_problem.php_contest_0_problem_185]: http://acm.sgu.ru/problem.php?contest=0&problem=185
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1486]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1486
[http_hi.baidu.com_kevin0602_blog_item_1d5be63b5bec9bec14cecb44.html]: http://hi.baidu.com/kevin0602/blog/item/1d5be63b5bec9bec14cecb44.html
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1904]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1904
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2060]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2060
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2594]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2594
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3041]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3041
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2226]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2226
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2195]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2195
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2400]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2400
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2516]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2516
[http_acm.pku.edu.cn_JudgeOnline_problem_id_3686]: http://acm.pku.edu.cn/JudgeOnline/problem?id=3686
[http_hi.baidu.com_kevin0602_blog_item_2829dc01d7143b087bec2c97.html]: http://hi.baidu.com/kevin0602/blog/item/2829dc01d7143b087bec2c97.html
[https_www.spoj.pl_problems_COVER]: https://www.spoj.pl/problems/COVER/
[http_hi.baidu.com_roba_blog_item_c842fdfac10d24dcb48f31d7.html]: http://hi.baidu.com/roba/blog/item/c842fdfac10d24dcb48f31d7.html
[http_acm.sgu.ru_problem.php_contest_0_problem_206]: http://acm.sgu.ru/problem.php?contest=0&problem=206
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1419]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1419
[http_acm.pku.edu.cn_JudgeOnline_problem_id_2989]: http://acm.pku.edu.cn/JudgeOnline/problem?id=2989
[http_acm.zju.edu.cn_show_problem.php_pid_1492]: http://acm.zju.edu.cn/show_problem.php?pid=1492
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1470]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1470
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1985]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1985
[http_acm.pku.edu.cn_JudgeOnline_problem_id_1986]: http://acm.pku.edu.cn/JudgeOnline/problem?id=1986
[http_acm.hnu.cn_8080_online_action_problem_type_show_id_11192_courseid_99]: http://acm.hnu.cn:8080/online/?action=problem&type=show&id=11192&courseid=99
[http_acm.hnu.cn_8080_online_action_problem_type_show_id_11277_courseid_109]: http://acm.hnu.cn:8080/online/?action=problem&type=show&id=11277&courseid=109