Cod sursa(job #2618665)

Utilizator adriangh3Adrian Gheorghiu adriangh3 Data 25 mai 2020 18:13:32
Problema Flux maxim Scor 60
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.82 kb
#include <stdio.h>
#include <queue>
#include <vector>
#include <limits.h>
#include <stdlib.h>
#define MAX 1000

bool bfs(int **graph, int n, int source, int sink, int *parent)
{
    std::queue<int> q;
    int viz[MAX] = {0};
    q.push(source);
    viz[source] = 1;
    while (!q.empty())
    {
        int nod = q.front();
        q.pop();
        for (int i = 0; i < n; i++)
        {
            if (graph[nod][i])
            {
                if (!viz[i])
                {
                    viz[i] = 1;
                    q.push(i);
                    parent[i] = nod;
                }
            }
        }
    }
    return viz[sink];
}

int main()
{
    FILE *in = fopen("maxflow.in", "r");
    FILE *out = fopen("maxflow.out", "w");
    int n, m;
    fscanf(in, "%d%d", &n, &m);
    int *parent = (int *)malloc(n * sizeof(int));
    int **graph = (int **)malloc(n * sizeof(int *));
    for (int i = 0; i < n; i++)
        graph[i] = (int *)malloc(n * sizeof(int));
    for (int i = 0; i < m; i++)
    {
        int nod1, nod2, cost;
        fscanf(in, "%d%d%d", &nod1, &nod2, &cost);
        nod1--;
        nod2--;
        graph[nod1][nod2] = cost;
    }
    int max_flow = 0;
    while (bfs(graph, n, 0, n - 1, parent))
    {
        int nod = n - 1;
        int mini = INT_MAX;
        while (nod != 0)
        {
            int nod1 = parent[nod];
            int nod2 = nod;
            mini = graph[nod1][nod2] < mini ? graph[nod1][nod2] : mini;
            nod = parent[nod];
        }
        nod = n - 1;
        while (nod != 0)
        {
            int nod1 = parent[nod];
            int nod2 = nod;
            graph[nod1][nod2] -= mini;
            graph[nod2][nod1] += mini;
            nod = parent[nod];
        }
        max_flow += mini;
    }
    fprintf(out, "%d\n", max_flow);
    fclose(in);
    fclose(out);
    return 0;
}