二分图最大权匹配

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int un,vn;//un左边点数，vn右边点数
int g[maxn][maxn];
int linker[maxn],lu[maxn],lv[maxn];
int slack[maxn];
bool visu[maxn],visv[maxn];
bool dfs( int u )
{
    visu[u] = true;
    for ( int v=0 ; v<vn ; v++ )
    {
        if ( visv[v] ) continue;
        int tmp = lu[u]+lv[v]-g[u][v];
        if ( tmp==0 )
        {
            visv[v] = true;
            if ( linker[v]==-1||dfs(linker[v]) )
            {
                linker[v] = u;
                return true;
            }
        }
        else if ( slack[v]>tmp )
            slack[v] = tmp;
    }
    return false;
}
int km()
{
    memset ( linker , -1 , sizeof(linker) );
    memset ( lv , 0 , sizeof(lv) );
    for ( int i=0 ; i<un ; i++ )
    {
        lu[i] = -inf;
        for ( int j=0 ; j<vn ; j++ )
            if ( g[i][j]>lu[i] ) lu[i] = g[i][j];
    }
    for ( int u=0 ; u<un ; u++ )
    {
        for ( int i=0 ; i<vn ; i++ )
            slack[i] = inf;
        while ( true )
        {
            memset ( visu , false , sizeof(visu) );
            memset ( visv , false , sizeof(visv) );
            if ( dfs(u) ) break;
            int d = inf;
            for ( int i=0 ; i<vn ; i++ )
                if ( !visv[i]&&d>slack[i] )
                    d = slack[i];
            for ( int i=0 ; i<un ; i++ )
                if ( visu[i] ) lu[i] -= d;
            for ( int i=0 ; i<vn ; i++ )
            {
                if ( visv[i] ) lv[i] += d;
                else slack[i] -= d;
            }
        }
    }
    int res = 0;
    for ( int i=0 ; i<vn ; i++ )
        if ( linker[i]!=-1 ) res += g[linker[i]][i];
    return res;
}