（补题 HDU 1068 ）Girls and Boys（二分图最大匹配）

原题链接戳我

题目大意

给你n个学生，编号从\(0\sim{n-1}\)，接下来每一行代表编号为\(i\)学生的“浪漫”关系人数以及其对应的学生编号\(S_i\),让你求出被包含在“浪漫关系”中最大的人数（就是有哪些人相互之间有关系）

Sample Input

7
0: (3) 4 5 6
1: (2) 4 6
2: (0)
3: (0)
4: (2) 0 1
5: (1) 0
6: (2) 0 1
3
0: (2) 1 2
1: (1) 0
2: (1) 0

Sample Output

5
2

解题思路

不多说先上图

loading......

代码样例

#include <bits/stdc++.h>
using namespace std;

const int maxn = 1000;
int e[maxn][maxn];
int match[maxn];
bool book[maxn];
int n;

bool dfs(int u)
{
    for (int i = 0; i < n; i++)
    {
        if (book[i] == false && e[u][i] == 1)
        {
            book[i] = true;
            if (match[i] == 0 || dfs(match[i]))
            {
                match[i] = u;
                return true;
            }
        }
    }
    return false;
}

int main()
{
    while (~scanf("%d", &n))
    {
        int sum = 0;
        memset(e, 0, sizeof(e));
        memset(match, 0, sizeof(match));
        for (int i = 0; i < n; i++)
        {
            int fr, m;
            char a,b,c,f;
            scanf("%d%c%c",&fr,&a,&f);
			scanf("%c%d%c",&b,&m,&c);
            // cout << f << " " << m << endl;
            for (int j = 0; j < m; j++)
            {
                int to;
                scanf("%d", &to);
                e[fr][to] = 1;
            }
        }
        for (int i = 0; i < n; i++)
        {
            memset(book, false, sizeof(book));
            if (dfs(i))
                sum++;
        }
        printf("%d\n", n - sum / 2);
    }
    return 0;
}