华为OJ平台题目：（练习用）挑7

亦凉 2022-08-05 10:29 210阅读 0赞

<table style="border-spacing:0px; border-collapse:collapse; width:960px; margin-bottom:35px; table-layout:fixed; color:rgb(92,92,92); font-family:'Helvetica Neue',Helvetica,Arial,'Lantinghei SC','Hiragino Sans GB','Microsoft YaHei','Wenquanyi Micro Hei',sans-serif; font-size:14px; line-height:20px; widows:1"> 
 <tbody style=""> 
 <tr style=""> 
 <th style="padding:8px 0px; font-weight:normal; width:86px; margin:1px; border:2px solid rgb(255,255,255); background-color:rgb(207,235,252)"> 描述 </th> 
 <td style="padding:8px 20px; word-break:break-all; word-wrap:break-word; border:2px solid rgb(255,255,255); width:872px; background-color:rgb(226,243,253)"> <pre style="overflow:hidden; font-family:monospace,monospace; font-size:1em; white-space:pre-wrap; word-wrap:break-word; line-height:24px">输出7有关数字的个数，包括7的倍数，还有包含7的数字（如17，27，37...70，71，72，73...）的个数 </pre> </td> 
 </tr> 
 <tr style=""> 
 <th style="padding:8px 0px; font-weight:normal; width:86px; margin:1px; border:2px solid rgb(255,255,255); background-color:rgb(207,235,252)"> 知识点</th> 
 <td style="padding:8px 20px; word-break:break-all; word-wrap:break-word; border:2px solid rgb(255,255,255); width:872px; background-color:rgb(226,243,253)"> 循环</td> 
 </tr> 
 <tr style=""> 
 <th style="padding:8px 0px; font-weight:normal; width:86px; margin:1px; border:2px solid rgb(255,255,255); background-color:rgb(207,235,252)"> 运行时间限制</th> 
 <td style="padding:8px 20px; word-break:break-all; word-wrap:break-word; border:2px solid rgb(255,255,255); width:872px; background-color:rgb(226,243,253)"> 0M</td> 
 </tr> 
 <tr style=""> 
 <th style="padding:8px 0px; font-weight:normal; width:86px; margin:1px; border:2px solid rgb(255,255,255); background-color:rgb(207,235,252)"> 内存限制</th> 
 <td style="padding:8px 20px; word-break:break-all; word-wrap:break-word; border:2px solid rgb(255,255,255); width:872px; background-color:rgb(226,243,253)"> 0</td> 
 </tr> 
 <tr style=""> 
 <th style="padding:8px 0px; font-weight:normal; width:86px; margin:1px; border:2px solid rgb(255,255,255); background-color:rgb(207,235,252)"> 输入</th> 
 <td style="padding:8px 20px; word-break:break-all; word-wrap:break-word; border:2px solid rgb(255,255,255); width:872px; background-color:rgb(226,243,253)"> 一个正整数N。(N不大于30000) </td> 
 </tr> 
 <tr style=""> 
 <th style="padding:8px 0px; font-weight:normal; width:86px; margin:1px; border:2px solid rgb(255,255,255); background-color:rgb(207,235,252)"> 输出</th> 
 <td style="padding:8px 20px; word-break:break-all; word-wrap:break-word; border:2px solid rgb(255,255,255); width:872px; background-color:rgb(226,243,253)"> 不大于N的与7有关的数字个数，例如输入20，与7有关的数字包括7,14,17. </td> 
 </tr> 
 <tr style=""> 
 <th style="padding:8px 0px; font-weight:normal; width:86px; margin:1px; border:2px solid rgb(255,255,255); background-color:rgb(207,235,252)"> 样例输入</th> 
 <td style="padding:8px 20px; word-break:break-all; word-wrap:break-word; border:2px solid rgb(255,255,255); width:872px; background-color:rgb(226,243,253)"> 20</td> 
 </tr> 
 <tr style=""> 
 <th style="padding:8px 0px; font-weight:normal; width:86px; margin:1px; border:2px solid rgb(255,255,255); background-color:rgb(207,235,252)"> 样例输出</th> 
 <td style="padding:8px 20px; word-break:break-all; word-wrap:break-word; border:2px solid rgb(255,255,255); width:872px; background-color:rgb(226,243,253)"> 3</td> 
 </tr> 
 </tbody> 
</table>

#include <iostream>
 
 using namespace std;
 
 int main()
 {
 	int N = 0, i = 0;
 	int count = 0, temp = 0;
 	bool flag = false;
 
 	while(cin >> N)
 	{
 		count = 0;
 		for(i = 7; i <= N; i++)
 		{
 			/* 判断该数据有没有包含7 */
 			temp = i;
 			flag = false;
 			if(temp % 7 == 0)
 			{
 				flag = true;
 			}
 			/* 如果temp不是7的倍数，再判断有没有哪一位有7 */
 			if(flag == false)
 			{
 				while(temp)
 				{
 					if(temp%10 == 7)
 					{
 						flag = true;
 						break;
 					}
 					temp = temp / 10;
 				}
 			}
 			
 			if(flag == true)
 			{
 				count++;
 			}
 		}
 		cout << count << endl;
 	}
 	return 0;
 }