BZOJ大视野 1059: [ZJOI2007]矩阵游戏 解题报告

二分图匹配，用行匹配列。

code:

/**************************************************************

    Problem: 1059

    Language: C++

    Result: Accepted

    Time:316 ms

    Memory:1744 kb

****************************************************************/

  

// Forever_LF

#include<cstdio>

#include<cstring>

#include<iostream>

usingnamespacestd;

  

structnode

{

    intx,y,next;

}a[40001]; intlen,first[201];

int L[201];

bool ev[201];

  

void ins( int x,inty )

{

    len++;

    a[len].x=x; a[len].y=y; 

    a[len].next = first[x]; first[x] = len;

}

bool ex( int x )

{

    for(intk=first[x];k;k=a[k].next )

    {

        inty=a[k].y;

        if( ev[y] )continue;

        ev[y] =true;

        if( !L[y] || ex( L[y] ) )

        {

            L[y] = x;

            returntrue;

        }

    }

    returnfalse;

}

  

int main()

{

    intn,m,t,i,j,l;

    boolv;

    scanf("%d",&m);

    while( m-- )

    {

        memset( first,0,sizeoffirst );

        memset( L,0,sizeofL );

        len = 0; v =true;

          

        scanf("%d",&n);

        for( i=1;i<=n;i++ )

            for( j=1;j<=n;j++ )

            {

                scanf("%d",&l);

                if( l ) ins( i,j );

            }

        for( i=1;i<=n;i++ )

        {

            memset( ev,false,sizeofev );

            if( !ex( i ) )

            {

                v =false; 

                break;

            }

        }

        if( v )printf("Yes\n");

        elseprintf("No\n");

    }

    return0;

}