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。

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#include <iostream>

#include <cstdio>

#include <cstdlib>

#include <cstring>

using namespace std;



#define maxn 205



bool 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;

}