poj 2239 Selecting Courses 最大二分匹配
把p,q化为一维之后,直接用匈牙利算法
#include<iostream> using namespace std; const int MAX = 200; bool arcs[MAX][MAX]; int match[MAX]; bool isvisit[MAX]; int n, m = 7*12; int find(int u) { for (int i = 1; i <= m; i++) if (arcs[u][i] && !isvisit[i]) { isvisit[i] = true; if (!match[i] || find(match[i])) { match[i] = u; return true; } } return false; } int main() { int t, p, q; while (cin >> n) { memset(arcs, false, sizeof(arcs)); memset(match, 0, sizeof(match)); for (int j = 1; j <= n; j++) { cin >> t; for (int i = 1; i <= t; i++) { cin >> p >> q; arcs[j][12*(p-1) + q] = true; } } int ans = 0; for (int i = 1; i <= n; i++) { memset(isvisit, false, sizeof(isvisit)); if (find(i)) ans++; } cout << ans << endl; } return 0; }