Cod sursa(job #318460)

Utilizator raduzerRadu Zernoveanu raduzer Data 28 mai 2009 16:57:20
Problema Flux maxim Scor 70
Compilator cpp Status done
Runda Arhiva educationala Marime 1.02 kb
#include <cstdio>
#include <cstring>

const int INF = 0x3f3f3f3f;
const int MAX_N = 1010;

int n, m, sol;
int c[MAX_N][MAX_N];
int f[MAX_N], up[MAX_N], q[MAX_N];

template <class T> T min(T a, T b) { return (a < b) ? a : b; }

int bf()
{
	memset(f, 0, sizeof(f));
	memset(up, 0, sizeof(up));
	memset(q, 0, sizeof(q));
	f[1] = INF;
	q[0] = 1;
	int l, r;
	
	for (l = r = 0; l <= r; ++l)
	{
		int nod = q[l];
		
		for (int i = 1; i <= n; ++i)
			if (c[nod][i] && f[i] == 0)
			{
				f[i] = min(f[nod], c[nod][i]);
				up[i] = nod;
				q[++r] = i;
			}
	}
	
	if (!f[n]) return 0;
	
	sol += f[n];
	
	for (int i = n; i != 1; i = up[i])
	{
		c[up[i]][i] -= f[n];
		c[i][up[i]] += f[n];
	}
	
	return 1;
}

int main()
{
	int x, y, z;
	freopen("maxflow.in", "r", stdin);
	freopen("maxflow.out", "w", stdout);
	
	scanf("%d %d", &n, &m);
	
	for (int i = 1; i <= m; ++i)
	{
		scanf("%d %d %d", &x, &y, &z);
		
		c[x][y] = z;
	}
	
	int ch = 1;
	
	while (ch) ch = bf();
	
	printf("%d\n", sol);
}