Network flow HDU 3549 flow problem

Network flow HDU 3549 flow problem

Title: http://acm.hdu.edu.cn/showproblem.php?pid=3549

Using the augmented path algorithm to solve the problem, there are two points to note:

1. Each time the augmentation, the reverse flow will be more line, at first did not notice, WA a few times ORZ

2. For the input data, the capacity should be updated incrementally.

Adjacency Matrix Storage # include <bits/stdc++.h>using namespace std;const int INF = 0x7fffffff;const int M = 15+5;int C[m][m];    Capacityint F[m][m];    Flowint Flow[m];       Current Flowsint p[m];    path//augmented path algorithm long long maxflow (int n) {long Long cnt = 0;        while (true) {queue<int> q;        Q.push (1);        memset (flow, 0, sizeof (flow));        FLOW[1] = INF;            while (!q.empty ()) {int u = q.front ();            Q.pop (); for (int v=1; v<=n; ++v) {if (U = v && c[u][v] > F[u][v] &&!flow[v]/* Avoid                    Non-loopback */) {Q.push (v);                    Flow[v] = min (Flow[u], c[u][v]-f[u][v]);                P[V] = u;  }}} if (flow[n]==0) break;        No augmentation, exit//For augmented//cout<<flow[n]<<endl;            for (int v=n; v! = 1; V=p[v]) {F[p[v]][v] + = Flow[n]; F[v][p[v]]-= flow[n]; Reverse update, there is inflow, outflow naturally should also increase!    WA a few times to find Orz} cnt + = Flow[n]; } return CNT;}    int main (void) {//freopen ("In.txt", "R", stdin);    int icase = 1;    int t = 0;    cin>>t;        while (t--) {memset (c, 0, sizeof (c));        memset (f, 0, sizeof (f));        int n, m;        scanf ("%d%d", &n, &m);            for (int i=0; i<m; ++i) {int s,e,v;            scanf ("%d%d%d", &s, &e, &v);       C[s][e] + = V; Incoming capacity to accumulate}//special case Direct judgment if (n <= 1 | | m < 1) {printf ("Case%d:0\n", icase            ++);        Continue        A long long cnt = Maxflow (n);    printf ("Case%d:%lld\n", icase++, CNT); } return 0;}

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Network flow HDU 3549 flow problem