hdu 1504最小点集覆盖

这题先用邻接矩阵打了试，TLE，改成邻接表，就过了。。

/*

 * hdu1054/win.cpp

 * Created on: 2012-8-14

 * 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 = 1600;

int N, mymatch[MAXN], temp[MAXN];

vector<int> mymap[MAXN];

bool visited[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 t, k, a;

    if(scanf("%d", &N) == EOF) {

        return false;

    }

    init();

    memset(temp, -1, sizeof(temp));

    bool flag = false;

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

        scanf("%d:(%d)", &a, &k);

        if(!flag) {

            if(k > 0) {

                temp[a] = 0;

                flag = true;

            }

        }

        for(int j = 0; j < k; j++) {

            scanf("%d", &t);

            if(temp[a] == 0) {

                temp[t] = 1;

                mymap[a].push_back(t);

            }else{

                temp[t] = 0;

                mymap[t].push_back(a);

            }

        }

    }

    return true;

}

int main() {

#ifndef ONLINE_JUDGE

    freopen("data.in", "r", stdin);

#endif

    while(buildgraph()) {

        printf("%d\n", hungary());

    }

    return 0;

}