hdu 2426 Interesting Housing Problem（KM模板）

判斷不可行 + 左右點數不同的模板

#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef int lint;
namespace KM {
    const int N = 505;
    const lint inf = 0x3f3f3f3f;
    int n,m;
    lint cost[N][N];
    lint lx[N], ly[N], match[N], slack[N];
    int prev[N];
    bool vy[N];

    void init(int _n,int _m) {
        n = _n;
        m = _m;
        for (int i = 1; i <= n; i++)
            for (int j = 1; j <= m; j++)
                cost[i][j] = -inf;
    }

    bool augment(int root) {
        fill(vy, vy + m + 1, false);
        fill(slack, slack + m + 1, inf);
        int py;
        match[py = 0] = root;
        do {
            vy[py] = true;
            int x = match[py], yy;
            lint delta = inf;
            for (int y = 1; y <= m; y++) {
                if (!vy[y]) {
                    if (lx[x] + ly[y] - cost[x][y] < slack[y]) {
                        slack[y] = lx[x] + ly[y] - cost[x][y];
                        prev[y] = py;
                    }
                    if (slack[y] < delta) {
                        delta = slack[y];
                        yy = y;
                    }
                }
            }
            if( delta >= inf || delta <= -inf ) return false;
            for (int y = 0; y <= m; y++) {
                if (vy[y]) {
                    lx[match[y]] -= delta;
                    ly[y] += delta;
                } else
                    slack[y] -= delta;
            }
            py = yy;
        } while (match[py] != -1);
        do {
            int pre = prev[py];
            match[py] = match[pre];
            py = pre;
        } while (py);
        return true;
    }

    bool KM(lint& Cost) {
        for( int i = 1;i <= m;i++ ) {
            ly[i] = 0;match[i] = -1;
        }
        for (int i = 1; i <= n; i++) {
            lx[i] = 0;
            for (int j = 1; j <= m; j++) lx[i] = max(lx[i], cost[i][j]);
        }
        for (int root = 1; root <= n; root++) {
            if(!augment(root))return false;
        }
        Cost = 0;
        for( int i = 1;i <= m;i++ ){
            if( match[i] != -1 ){
                Cost += cost[match[i]][i];
            }
        }
        return true;
    }
}
int main(){
    int n,e,m;
    int ca = 0;
    while(3==scanf("%d%d%d",&n,&m,&e)){
        KM::init(n,m);
        int u,v,w;
        for( int i = 1;i <= e;i++ ){
            scanf("%d%d%d",&u,&v,&w);
            u++;v++;
            if(w >= 0)
                KM::cost[u][v] = max( KM::cost[u][v],w);
        }
        int ans;
        if( n > m ){
            ans = -1;
        }else {
            bool flag = KM::KM(ans);
            if (!flag) {
                ans = -1;
            }
        }
        printf("Case %d: %d\n",++ca,ans);
    };
    return 0;
}