HDU 3395 Special Fish【最大权匹配】

题意：最大权匹配

分析：最大全匹配

代码：

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

const int maxn = 105;
const int INF = 2000000000;

bool Sx[maxn], Sy[maxn];
int Lx[maxn], Ly[maxn];
int Link[maxn];
int W[maxn][maxn];
int n, m;

bool Find(int i) {
    Sx[i] = true;
    for(int j = 1; j <= m; j++) {
        if(!Sy[j] && Lx[i] + Ly[j] == W[i][j]) {
            Sy[j] = true;
            if(Link[j] == 0 || Find(Link[j])) {
                Link[j] = i;
                return true;
            }
        }
    }
    return false;
}

int KM() {
    for(int i = 1; i <= n;i++) {
        Lx[i] = 0;
        for(int j = 1; j <= m; j++) {
            Lx[i] = max(Lx[i], W[i][j]);
        }
    }
    memset(Ly, 0, sizeof(Ly));
    memset(Link, 0, sizeof(Link));
    for(int v = 1; v <= n; v++) {
        memset(Sx, 0, sizeof(Sx));
        memset(Sy, 0, sizeof(Sy));
        while(1) {
            if(Find(v)) break;
            int dmin = INF;
            for(int i = 1; i <= n; i++) {
                if(Sx[i]) {
                    for(int j = 1; j <= m; j++) {
                        if(!Sy[j] && Lx[i] + Ly[j] - W[i][j] < dmin) {
                            dmin = Lx[i] + Ly[j] - W[i][j];
                        }
                    }
                }
            }
            for(int i = 1; i <= n; i++) {
                if(Sx[i]) {
                    Lx[i] -= dmin;
                    Sx[i] = 0;
                }
            }
            for(int i = 1; i <= m; i++) {
                if(Sy[i]) {
                    Ly[i] += dmin;
                    Sy[i] = 0;
                }
            }
        }
    }
    int sum = 0;
    for(int i = 1; i <= n; i++) {
        sum += W[Link[i]][i];
    }
    return sum;
}

int val[maxn];
char mat[maxn][maxn];
int main() {
    while(scanf("%d",&n) && n) {
        memset(W, 0, sizeof(W));
        for(int i = 1; i <= n; i++) {
            scanf("%d",&val[i]);
        }
        for(int i = 1; i <= n; i++) {
            scanf("%s",mat[i]);
        }
        for(int i = 1; i <= n; i++) {
            for(int j = 0; j < n; j++) {
                if(i == j + 1) continue;
                if(mat[i][j] == '1') {
                    W[i][j + 1] = val[i] ^ val[j + 1];
                }
            }
        }
        m = n;
        printf("%d
",KM());
    }
    return 0;
}