[HDOJ6118] 度度熊的交易计划（最小费用可行流）

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=6118

这个建图炒鸡简单，中间的图去掉重边后丢进去就行。

建图的时候费用实际上是价值，所以正的费用就不用跑了，相当于求费用可行流。

/*
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┓┏┓┏┓┃キリキリ♂ mind！
┛┗┛┗┛┃＼○／
┓┏┓┏┓┃ /
┛┗┛┗┛┃ノ)
┓┏┓┏┓┃
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┓┏┓┏┓┃
┃┃┃┃┃┃
┻┻┻┻┻┻
*/
#include <bits/stdc++.h>
using namespace std;
#define fr first
#define sc second
#define cl clear
#define BUG puts("here!!!")
#define W(a) while(a--)
#define pb(a) push_back(a)
#define Rint(a) scanf("%d", &a)
#define Rll(a) scanf("%I64d", &a)
#define Rs(a) scanf("%s", a)
#define Cin(a) cin >> a
#define FRead() freopen("in", "r", stdin)
#define FWrite() freopen("out", "w", stdout)
#define Rep(i, len) for(int i = 0; i < (len); i++)
#define For(i, a, len) for(int i = (a); i < (len); i++)
#define Cls(a) memset((a), 0, sizeof(a))
#define Clr(a, x) memset((a), (x), sizeof(a))
#define Full(a) memset((a), 0x7f7f7f, sizeof(a))
#define lrt rt << 1
#define rrt rt << 1 | 1
#define pi 3.14159265359
#define RT return
#define lowbit(x) x & (-x)
#define onenum(x) __builtin_popcount(x)
typedef long long LL;
typedef long double LD;
typedef unsigned long long ULL;
typedef pair<int, int> pii;
typedef pair<string, int> psi;
typedef pair<LL, LL> pll;
typedef map<string, int> msi;
typedef vector<int> vi;
typedef vector<LL> vl;
typedef vector<vl> vvl;
typedef vector<bool> vb;

typedef struct Node {
    int u, v, next;
    LL c, w;
}Node;

const int maxn = 550;
const int maxm = 1010;
const int inf = 0x7f7f7f7f;
const LL mod = 0x3f3f3f3fLL;
int n, m;
int a[maxn], b[maxn], c[maxn], d[maxn];
int f[maxn][maxn];


int tot, head[maxn];
LL dist[maxn];
LL cost, flow;
Node e[1001000];
int pre[maxn];
bool visit[maxn];
queue<int> Q;
int S, T, N;

void init() {
    S = T = N = 0;
    memset(head, -1, sizeof(head));
    tot = 0;
}

void adde(int u, int v, LL c, LL w) {
    e[tot].u = u; e[tot].v = v; e[tot].c = c; e[tot].w = w; e[tot].next = head[u]; head[u] = tot++;
    e[tot].u = v; e[tot].v = u; e[tot].c = 0; e[tot].w = -w; e[tot].next = head[v]; head[v] = tot++;
}
bool spfa(int s, int t, int n) {
    int i;
    for(i = 0; i <= n; i++) {
        dist[i] = inf;
        visit[i] = 0;
        pre[i] = -1;
    }
    while(!Q.empty()) Q.pop();
    Q.push(s);
    visit[s] = true;
    dist[s] = 0;
    pre[s] = -1;
    while(!Q.empty()) {
        int u = Q.front();
        visit[u] = false;
        Q.pop();
        for(int j = head[u]; j != -1; j = e[j].next) {
            if(e[j].c > 0 && dist[u] + e[j].w < dist[e[j].v]) {
                dist[e[j].v] = dist[u] + e[j].w;
                pre[e[j].v] = j;
                if(!visit[e[j].v]) {
                    Q.push(e[j].v);
                    visit[e[j].v] = true;
                }
            }
        }
    }
    return dist[t] < 0;
    // if(dist[t] == inf) return false;
    // else return true;
}
LL ChangeFlow(int t) {
    LL det = mod;
    int u = t;
    while(~pre[u]) {
        u = pre[u];
        det = min(det, e[u].c);
        u = e[u].u;
    }
    u = t;
    while(~pre[u]) {
        u = pre[u];
        e[u].c -= det;
        e[u ^ 1].c += det;
        u = e[u].u;
    }
    return det;
}
LL MinCostFlow(int s, int t, int n) {
    LL mincost, maxflow;
    mincost = maxflow = 0;
    while(spfa(s, t, n)) {
        LL det = ChangeFlow(t);
        mincost += det * dist[t];
        maxflow += det;
    }
    cost = mincost;
    flow = maxflow;
    return mincost;
}

inline bool scan_d(int &num) {
    char in;bool IsN=false;
    in=getchar();
    if(in==EOF) return false;
    while(in!='-'&&(in<'0'||in>'9')) in=getchar();
    if(in=='-'){ IsN=true;num=0;}
    else num=in-'0';
    while(in=getchar(),in>='0'&&in<='9'){
        num*=10,num+=in-'0';
    }
    if(IsN) num=-num;
    return true;
}

signed main() {
    // freopen("in", "r", stdin);
    int u, v, w;
    while(scan_d(n)) {
        scan_d(m);
        For(i, 1, n+1) {
            For(j, 1, n+1) {
                f[i][j] = inf;
            }
        }
        For(i, 1, n+1) {
            scan_d(a[i]); scan_d(b[i]);
            scan_d(c[i]); scan_d(d[i]);
            f[i][i] = 0;
        }
        Rep(i, m) {
            scan_d(u); scan_d(v); scan_d(w);
            if(f[u][v] > w) {
                f[u][v] = f[v][u] = w;
            }
        }
        init();
        S = 0, T = n + 1, N = T + 1;
        For(i, 1, n+1) {
            adde(i, T, d[i], -c[i]);
            adde(S, i, b[i], a[i]);
        }
        For(i, 1, n+1) {
            For(j, 1, n+1) {
                if(i == j) continue;
                if(f[i][j] != inf) adde(i, j, inf, f[i][j]);
            }
        }
        LL ret = -MinCostFlow(S, T, N);
        printf("%d\n", (int)ret);
    }
    return 0;
}