最小費用最大流的模板

自己的模板：鄰接表。#include<iostream>using namespace std; struct{    int v, cap, cost, next, re;    //  re記錄逆邊的下標。}edge[eMax];int n, m, ans;int k, edgeHead[nMax];int que[nMax], pre[nMax], dis[nMax];bool vis[nMax]; void addEdge(int u, int v, int ca, int co){    edge[k].v = v;    edge[k].cap = ca;    edge[k].cost = co;    edge[k].next = edgeHead[u];    edge[k].re = k + 1;        edgeHead[u] = k ++;    edge[k].v = u;    edge[k].cap = 0;    edge[k].cost = -co;    edge[k].next = edgeHead[v];    edge[k].re = k - 1;    edgeHead[v] = k ++;} bool spfa(){                  //  源點為0，匯點為n。    int i, head = 0, tail = 1;    for(i = 0; i <= n; i ++){        dis[i] = inf;        vis[i] = false;    }    dis[0] = 0;    que[0] = 0;    vis[u] = true;    while(tail > head){       //  這裡最好用隊列，有廣搜的意思，堆棧像深搜。        int u = que[head ++];        for(i = edgeHead[u]; i != 0; i = edge[i].next){            int v = edge[i].v;            if(edge[i].cap && dis[v] > dis[u] + edge[i].cost){                dis[v] = dis[u] + edge[i].cost;                pre[v] = i;                if(!vis[v]){                    vis[v] = true;                    que[tail ++] = v;                }            }        }        vis[u] = false;    }    if(dis[n] == inf) return false;    return true;} void end(){    int u, p, sum = inf;    for(u = n; u != 0; u = edge[edge[p].re].v){        p = pre[u];        sum = min(sum, edge[p].cap);    }    for(u = n; u != 0; u = edge[edge[p].re].v){        p = pre[u];        edge[p].cap -= sum;        edge[edge[p].re].cap += sum;        ans += sum * edge[p].cost;     //  cost記錄的為單位流量費用，必須得乘以流量。    }} int main(){    ...    ans = 0;    while(spfa()) end();    ...    return 0;} 自己的模板：鄰接矩陣。#include<iostream>using namespace std; int n, ans;int cap[Max][Max], pre[Max];int cost[Max][Max], dis[Max];int que[Max];bool vis[Max]; bool spfa(){                  //  源點為0，匯點為n。    int i, head = 0, tail = 1;    for(i = 0; i <= n; i ++){        dis[i] = inf;        vis[i] = false;    }    dis[0] = 0;    que[0] = 0;    vis[u] = true;    while(tail != head){      //  迴圈隊列。        int u = que[head];        for(i = 0; i <= n; i ++)            if(cap[u][i] && dis[i] > dis[u] + cost[u][i]){    //  存在路徑，且權值變小。                dis[i] = dis[u] + cost[u][i];                pre[i] = u;                if(!vis[i]){                    vis[i] = true;                    que[tail ++] = i;                    if(tail == Max) tail = 0;                }            }        vis[u] = false;        head ++;        if(head == Max) head = 0;    }    if(dis[n] == inf) return false;    return true;} void end(){    int i, sum = inf;    for(i = n; i != 0; i = pre[i])        sum = min(sum, cap[pre[i]][i]);    for(i = n; i != 0; i = pre[i]){        cap[pre[i]][i] -= sum;        cap[i][pre[i]] += sum;        ans += cost[pre[i]][i] * sum;   //  cost[][]記錄的為單位流量費用，必須得乘以流量。    }} int main(){    ....    ans = 0;    while(spfa()) end();    ....    return 0;}