Codeforces 965B 题解报告

一、题目

http://codeforces.com/contest/965/problem/B

二、分析

当k = 1时，取第一个’.’的坐标即可
当k > 1时，需要求出每一个点在上下左右四个方向所能到达的最远处，记为up, down, left, right，再取上下方向和左右方向的和的最大值，即
max(0, up + down - k) + max(0, left + right - k)

三、程序

n, k = map(int, input().split())
a = []
for i in range(n):
    a.append(input())
maxans = 0
xans = 0
yans = 0
for i in range(n):
    for j in range(n):
        curans = 0
        up = 0
        while up < k and i - up >= 0 and a[i - up][j] == '.':
            up += 1
        down = 0
        while down < k and i + down < n and a[i + down][j] == '.':
            down += 1
        curans += max(0, down + up - k)
        if k != 1:
            left = 0
            while left < k and j - left >= 0 and a[i][j - left] == '.':
                left += 1
            right = 0
            while right < k and j + right < n and a[i][j + right] == '.':
                right += 1
            curans += max(0, right + left - k)
        if curans > maxans:
            maxans = curans
            xans = i
            yans = j
print(xans + 1, yans + 1)