费用流板子

还是一道板子题。。先练练手

#include 
    
     #define INF 0x3f3f3f3f#define full(a, b) memset(a, b, sizeof a)using namespace std;typedef long long ll;inline int lowbit(int x){ return x & (-x); }inline int read(){    int X = 0, w = 0; char ch = 0;    while(!isdigit(ch)) { w |= ch == '-'; ch = getchar(); }    while(isdigit(ch)) X = (X << 3) + (X << 1) + (ch ^ 48), ch = getchar();    return w ? -X : X;}inline int gcd(int a, int b){ return a % b ? gcd(b, a % b) : b; }inline int lcm(int a, int b){ return a / gcd(a, b) * b; }template
     
      inline T max(T x, T y, T z){ return max(max(x, y), z); }template
      
       inline T min(T x, T y, T z){ return min(min(x, y), z); }template
       
        inline A fpow(A x, B p, C lyd){    A ans = 1;    for(; p; p >>= 1, x = 1LL * x * x % lyd)if(p & 1)ans = 1LL * x * ans % lyd;    return ans;}const int N = 5005;const int M = 50005;int n, m, s, t, head[N], cnt, inq[N], pre[N], incf[N], dist[N], ans, mf;struct Edge { int v, next, f, cost; } edge[M<<1];void addEdge(int a, int b, int f, int cost){    edge[cnt].v = b, edge[cnt].f = f, edge[cnt].cost = cost, edge[cnt].next = head[a], head[a] = cnt ++;    edge[cnt].v = a, edge[cnt].f = 0, edge[cnt].cost = -cost, edge[cnt].next = head[b], head[b] = cnt ++;}bool spfa(){    full(dist, INF), full(inq, false);    full(pre, 0), full(incf, INF);    queue
        
          q;    q.push(s);    dist[s] = 0, inq[s] = true;    while(!q.empty()){        int cur = q.front(); q.pop();        inq[cur] = false;        for(int i = head[cur]; i != -1; i = edge[i].next){            int u = edge[i].v;            if(edge[i].f > 0 && dist[u] > dist[cur] + edge[i].cost){                dist[u] = dist[cur] + edge[i].cost;                pre[u] = i, incf[u] = min(incf[cur], edge[i].f);                if(!inq[u]) q.push(u), inq[u] = true;            }        }    }    return dist[t] != INF;}void mcmf(){    while(spfa()){        int cur = t;        while(cur != s){            int i = pre[cur];            edge[i].f -= incf[t], edge[i^1].f += incf[t];            cur = edge[i^1].v;        }        mf += incf[t];        ans += dist[t] * incf[t];    }}int main(){    full(head, -1), cnt = 2;    n = read(), m = read(), s = read(), t = read();    for(int i = 0; i < m; i ++){        int u = read(), v = read(), w = read(), c = read();        addEdge(u, v, w, c);    }    mcmf();    printf("%d %d\n", mf, ans);    return 0;}