[网络流24题]飞行员配对方案问题

链接

题意：二分图模板

Code(匈牙利算法)

#include<bits/stdc++.h>
#define N 205
using namespace std;
int n,m,ans;
int link[N][N];
int match[N],book[N];

template <class T>
void read(T &x)
{
    char c;int sign=1;
    while((c=getchar())>'9'||c<'0') if(c=='-') sign=-1; x=c-48;
    while((c=getchar())>='0'&&c<='9') x=(x<<1)+(x<<3)+c-48; x*=sign;
}

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

int main()
{
    read(m);read(n);
    int x,y;
    while(1)
    {
        read(x);read(y);
        if(x==-1||y==-1) break;
        link[x][y]=link[y][x]=1;
    }
    for(int i=m+1;i<=n+m;++i)
    {
        memset(book,0,sizeof(book));
        if(dfs(i)) ++ans;
    }
    if(!ans)
    {
        printf("No Solution!");
        return 0;
    }
    printf("%d\n",ans);
    for(int i=1;i<=m;++i)
    {
        if(match[i]) printf("%d %d\n",i,match[i]);
    }
    return 0;
}