Cod sursa(job #1451633)

Utilizator FluxFlux maxim Flux Data 17 iunie 2015 22:05:48
Problema Flux maxim Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 2.27 kb
/*
*/
 
//#pragma comment(linker, "/STACK:16777216")
#include <fstream>
#include <iostream>
#include <string>
#include <complex>
#include <math.h>
#include <set>
#include <vector>
#include <map>
#include <queue>
#include <stdio.h>
#include <stack>
#include <algorithm>
#include <list>
#include <ctime>
#include <memory.h>
#include <ctime> 
 
#define y0 sdkfaslhagaklsldk
#define y1 aasdfasdfasdf
#define yn askfhwqriuperikldjk
#define j1 assdgsdgasghsf
#define tm sdfjahlfasfh
#define lr asgasgash
 
#define eps 1e-9
#define M_PI 3.141592653589793
#define bs 99991
#define bsize 256
 
using namespace std;
const int MAXN = 1005;

struct edge {
	int a, b, cap, flow;
};
 
int n, s, t, d[MAXN], ptr[MAXN], q[MAXN];
vector<edge> e;
vector<int> g[MAXN];
 
void add_edge (int a, int b, int cap) {
	edge e1 = { a, b, cap, 0 };
	edge e2 = { b, a, 0, 0 };
	g[a].push_back ((int) e.size());
	e.push_back (e1);
	g[b].push_back ((int) e.size());
	e.push_back (e2);
}
 
bool bfs() {
	int qh=0, qt=0;
	q[qt++] = s;
	memset (d, -1, n * sizeof d[0]);
	d[s] = 0;
	while (qh < qt && d[t] == -1) {
		int v = q[qh++];
		for (size_t i=0; i<g[v].size(); ++i) {
			int id = g[v][i],
				to = e[id].b;
			if (d[to] == -1 && e[id].flow < e[id].cap) {
				q[qt++] = to;
				d[to] = d[v] + 1;
			}
		}
	}
	return d[t] != -1;
}
 
int dfs (int v, int flow) {
	if (!flow)  return 0;
	if (v == t)  return flow;
	for (; ptr[v]<(int)g[v].size(); ++ptr[v]) {
		int id = g[v][ptr[v]],
			to = e[id].b;
		if (d[to] != d[v] + 1)  continue;
		int pushed = dfs (to, min (flow, e[id].cap - e[id].flow));
		if (pushed) {
			e[id].flow += pushed;
			e[id^1].flow -= pushed;
			return pushed;
		}
	}
	return 0;
}
 
int dinic() {
	int flow = 0;
	for (;;) {
		if (!bfs())  break;
		memset (ptr, 0, n * sizeof ptr[0]);
		while (int pushed = dfs (s, 10000000))
			flow += pushed;
	}
	return flow;
}
int m;

int main(){
freopen("maxflow.in","r",stdin);
freopen("maxflow.out","w",stdout);
//freopen("F:/in.txt","r",stdin);
//freopen("F:/output.txt","w",stdout);
ios_base::sync_with_stdio(0);
//cin.tie(0);

cin>>n>>m;
for (;m;--m)
{
	int a,b,q;
	cin>>a>>b>>q;
	add_edge(a,b,q);
}
s=1;
t=n;
n++;
cout<<dinic()<<endl;

//cin.get();cin.get();
return 0;}