P3654 First Step (ファーストステップ)

// Problem: P3654 First Step (ファーストステップ)
// Contest: Luogu
// URL: https://www.luogu.com.cn/problem/P3654
// Memory Limit: 125 MB
// Time Limit: 1000 ms
// User: Pannnn
 
#include <bits/stdc++.h>
 
using namespace std;
 
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0);
    
    int r, c, k;
    cin >> r >> c >> k;
    
    char info[110][110] = { 0 };
    for (int i = 1; i <= r; ++i) {
        for (int j = 1; j <= c; ++j) {
            cin >> info[i][j];
        }
    }
    
    // 以每个点为起始，判断其向右，向下是否能站立
    int cnt = 0;
    for (int i = 1; i <= r; ++i) {
        for (int j = 1; j <= c; ++j) {
            bool flag = true;
            for (int m = 0; m < k; ++m) {
                if (info[i][j + m] != '.') {
                    flag = false;
                    break;
                }
            }
            if (flag) {
                ++cnt;
            } else {
                flag = true;
            }
            /*
                注意当k为1时，向右向下会重复
            */
            if (k == 1) {
                continue;
            }
            for (int m = 0; m < k; ++m) {
                if (info[i + m][j] != '.') {
                    flag = false;
                    break;
                }
            }
            if (flag) {
                ++cnt;
            }
        }
    }
    cout << cnt << endl;
    return 0;
}