BZOJ4950 Wf2017Mission Improbable（二分图匹配）

#include<iostream> 
#include<cstdio>
#include<cmath>
#include<cstdlib>
#include<cstring>
#include<algorithm>
using namespace std;
#define ll long long
#define N 110
char getc(){char c=getchar();while ((c<‘A‘||c>‘Z‘)&&(c<‘a‘||c>‘z‘)&&(c<‘0‘||c>‘9‘)) c=getchar();return c;}
int gcd(int n,int m){return m==0?n:gcd(m,n%m);}
int read()
{
    int x=0,f=1;char c=getchar();
    while (c<‘0‘||c>‘9‘) {if (c==‘-‘) f=-1;c=getchar();}
    while (c>=‘0‘&&c<=‘9‘) x=(x<<1)+(x<<3)+(c^48),c=getchar();
    return x*f;
}
int n,m,a[N][N],r[N],c[N],p[N<<1],match[N<<1],flag[N<<1],t;
ll tot;
struct data{int to,nxt;
}edge[N*N<<1];
void addedge(int x,int y){t++;edge[t].to=y,edge[t].nxt=p[x],p[x]=t;}
bool hungary(int k,int f)
{
    for (int i=p[k];i;i=edge[i].nxt)
    if (flag[edge[i].to]!=f)
    {
        flag[edge[i].to]=f;
        if (!match[edge[i].to]||hungary(match[edge[i].to],f))
        {
            match[edge[i].to]=k;
            return 1;
        }
    }
    return 0;
}
int main()
{
#ifndef ONLINE_JUDGE
    freopen("bzoj4950.in","r",stdin);
    freopen("bzoj4950.out","w",stdout);
    const char LL[]="%I64d\n";
#else
    const char LL[]="%lld\n";
#endif
    n=read(),m=read();
    for (int i=1;i<=n;i++)
        for (int j=1;j<=m;j++)
        {
            a[i][j]=read();
            int x=max(a[i][j]-1,0);
            tot+=x,r[i]=max(r[i],x),c[j]=max(c[j],x);
        }
    for (int i=1;i<=n;i++) tot-=r[i];
    for (int i=1;i<=m;i++) tot-=c[i];
    for (int i=1;i<=n;i++)
        for (int j=1;j<=m;j++)
        if (r[i]==c[j]&&a[i][j]) addedge(i,j+n);
    for (int i=1;i<=n;i++) hungary(i,i);
    for (int i=1;i<=m;i++) if (match[n+i]) tot+=c[i];
    cout<<tot;
    return 0;
}