poj3692

最大独立集，把不认识的男女看成是有矛盾的，要选出一些互相没有矛盾的男女。

#include <iostream>
#include <cstdio>
#include <cstdlib>
#include <cstring>
using namespace std;#define maxn 205bool g[maxn][maxn];
int uN, vN, m;
int xM[maxn], yM[maxn];
bool chk[maxn];void input()
{for (int i = 0; i < m; i++){int a, b;scanf("%d%d", &a, &b);g[--a][--b] = true;}for (int i = 0; i < uN; i++)for (int j = 0; j < vN; j++)g[i][j] = !g[i][j];
}bool SearchPath(int u)
{int v;for (v = 0; v < vN; v++)if (g[u][v] && !chk[v]){chk[v] = true;if (yM[v] == -1 || SearchPath(yM[v])){yM[v] = u;xM[u] = v;return true;}}return false;
}int MaxMatch()
{int u, ret = 0;memset(xM, -1, sizeof(xM));memset(yM, -1, sizeof(yM));for (u = 0; u < uN; u++){if (xM[u] == -1){memset(chk, false, sizeof(chk));if (SearchPath(u))ret++;}}return ret;
}int main()
{//freopen("t.txt", "r", stdin);int t = 0;while (scanf("%d%d%d", &uN, &vN, &m), uN | vN | m){t++;memset(g, 0, sizeof(g));input();printf("Case %d: %d\n", t, uN + vN - MaxMatch());}return 0;
}