AcWing373 Wa on test#3求调

Question

AcWing 373,WA On test#3,code:

# include <bits/stdc++.h>

# define ffor(i,name) \
    for (auto i = name.begin (); i != name.end (); i ++)

using namespace std;

typedef long long ll;

typedef pair <int, int> pii;

int n, m, k, x, y, sum, p[205];

bool a[205][205], vis[205];

bool dfs (int x) {

    for (int i = 0; i < m; ++ i)
        if (! vis[i] && a[x][i]) {

            vis[i] = 1;

            if (! p[i] || dfs (p[i]))
                return p[i] = x, 1;

        }

    return 0;

}

int main () {

    ios::sync_with_stdio (0);

    cin.tie (0);

    cout.tie (0);

    cin >> n >> m >> k;

    for (int i = 0; i < n; ++ i)
        for (int j = 0; j < m; ++ j)
            a[i][j] = 1;

    while (k --) {

        cin >> x >> y;

        a[x - 1][y - 1] = 0;

    }

    for (int i = 0; i < n; ++ i) {

        for (int k = 0; k < m; ++ k)
            vis[k] = 0;

        sum += dfs (i);

    }

    cout << sum;

    return 0;

}