hdu1498最小点集覆盖

对于每一种颜色的气球都建一次图求最大匹配即可。

/*
 * hdu1498/win.cpp
 * Created on: 2012-8-16
 * Author    : ben
 */
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <queue>
#include <set>
#include <map>
#include <stack>
#include <string>
#include <vector>
#include <deque>
#include <list>
#include <functional>
#include <numeric>
#include <cctype>
using namespace std;
const int MAXN = 200;
vector<int> mymap[MAXN];
int N, M, mymatch[MAXN];
bool visited[MAXN];
int matrixs[MAXN][MAXN];
void init() {
    for(int i = 0; i < N; i++) {
        mymap[i].clear();
    }
}
bool dfs(int k) {
    int t, I;
    for(int i = 0; i < (int)mymap[k].size(); i++) {
        I = mymap[k][i];
        if(!visited[I]) {
            visited[I] = true;
            t = mymatch[I];
            mymatch[I] = k;
            if(t == -1 || dfs(t)) {
                return true;
            }
            mymatch[I] = t;
        }
    }
    return false;
}
int hungary () {
    memset(mymatch, -1, sizeof(mymatch));
    int ans = 0;
    for (int i = 0; i < N; i++) {
        memset(visited, false, sizeof(visited));
        if (dfs(i)) {
            ans++;
        }
    }
    return ans;
}
bool buildgraph(int k) {
    init();
    for (int i = 0; i < N; i++) {
        for(int j = 0; j < N; j++) {
            if(matrixs[i][j] == k) {
                mymap[i].push_back(j);
            }
        }
    }
    return true;
}
int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int k;
    bool flags[52];
    char str[500];
    while(scanf("%d%d", &N, &k) == 2) {
        if(N == 0 && k == 0) {
            break;
        }
        for(int i = 0; i < N; i++) {
            for(int j = 0; j < N; j++) {
                scanf("%d", &matrixs[i][j]);
            }
        }
        for(int i = 1; i <= 50; i++) {
            buildgraph(i);
            flags[i] = (hungary() <= k);
        }
        char *p = str;
        for(int i = 1; i <= 50; i++) {
            if(!flags[i]) {
                p += sprintf(p, "%d ", i);
            }
        }
        if(p == str) {
            puts("-1");
        }else {
            int len = strlen(str);
            str[len - 1] = 0;
            puts(str);
        }
    }
    return 0;
}