hdu2063 过山车二分图匹配

Posted 2022-11-23

题目链接：​​http://acm.hdu.edu.cn/showproblem.php?pid=2063​​​
题意：中文题
解析：二分图匹配裸题

#include <bits/stdc++.h>
using namespace std;
const int maxn = 5000;
struct node

    int to,next;
edge[maxn];
int head[maxn],cnt;
int match[maxn],vis[maxn];
void init()

    memset(head,-1,sizeof(head));
    memset(match,0,sizeof(match));
    cnt = 0;

void addEdge(int from,int to)

    edge[cnt].to = to;
    edge[cnt].next = head[from];
    head[from] = cnt++;

bool dfs(int u)

    for(int i=head[u];i!=-1;i = edge[i].next)
    
        int v = edge[i].to;
        if(vis[v]) continue;
        vis[v] = 1;
        if(!match[v] || dfs(match[v]))
        
            match[v] = u;
            match[u] = v;
            return true;
        
    
    return false;

int main(void)

    int k;
    while(~scanf("%d",&k)&&k)
    
        int n,m;
        init();
        scanf("%d %d",&m,&n);
        for(int i=0;i<k;i++)
        
            int x,y;
            scanf("%d %d",&x,&y);
            addEdge(x,y+m);
        
        int ans = 0;
        for(int i=1;i<=m;i++)
        
            memset(vis,0,sizeof(vis));
            if(dfs(i))
                ans++;
        
        printf("%d\\n",ans);
    
    return 0;