题解 | 小红的矩阵染色

#include <bits/stdc++.h>
using namespace std;

int main() {
    int n, m, k;
    cin >> n >> m >> k;
    vector<string> grid(n);
    for (int i = 0; i < n; ++i) cin >> grid[i];
    vector<int> nums;
    for (int i = 0; i < m; ++i){
        int j = 0;
        int cnt = 1;
        while (j < n){
            int start = j;
            j++;
            while (j < n && grid[start][i] == grid[j][i] && grid[j][i] == 'o'){
                cnt++;
                j++;
            }
            if (cnt > 1)    nums.push_back(cnt);
            cnt = 1;
        }
    }
    sort(nums.begin(), nums.end(), greater<int>());
    int ans = 0, s = 0;
    for (int c: nums){
        if (k - s > c) ans += c - 1;
        else{
            ans += k - s - 1;
            break;
        }
        s += c;
    }
    cout << ans;
}