KMアルゴリズム（二分割図の最大権マッチ）

http://blog.163.com/huangbingliang@yeah/blog/static/9416139920191044527/
複雑度O(n^3)です

#include <stdio.h>
#include <string.h>
#include <algorithm>

using namespace std;

const int N = 305;

const int Inf = 1e9;

int top,match[N];

int n,fix,w[N][N],va[N],vb[N];

bool visx[N],visy[N];

bool dfs(int u)
{
    visx[u] = true;
    for(int v=1;v<=n;v++)
    {
        if(visy[v])
            continue;
        if(va[u]+vb[v] == w[u][v])
        {
            visy[v] = true;
            if(!match[v] || dfs(match[v]))
            {
                match[v] = u;
                return true;
            }
        }
        else
            fix = min(fix,va[u]+vb[v]-w[u][v]);
    }
    return false;
}

int KM()
{
    memset(vb,0,sizeof(vb));
    memset(match,0,sizeof(match));
    for(int i=1;i<=n;i++)
    {
        while(1)
        {
            memset(visx,false,sizeof(visx));
            memset(visy,false,sizeof(visy));
            fix = Inf;
            if(dfs(i))
                break;
            if(fix == Inf)
                return -1;
            for(int i=1;i<=n;i++)
            {
                if(visx[i])
                    va[i] -= fix;
                if(visy[i])
                    vb[i] += fix;
            }
        }
    }
    int res = 0;
    for(int i=1;i<=n;i++)
        res += va[i] + vb[i];
    return res;
}

int main()
{
    while(~scanf("%d",&n))
    {
        memset(va,0,sizeof(va));
        for(int i=1;i<=n;i++)
            for(int j=1;j<=n;j++)
            {
                scanf("%d",&w[i][j]);
                va[i] = max(va[i],w[i][j]);
            }
        printf("%d
",KM());
    }
    return 0;
}