Cod sursa(job #2226576)

Utilizator inquisitorAnders inquisitor Data 30 iulie 2018 12:52:54
Problema BFS - Parcurgere in latime Scor 0
Compilator cpp Status done
Runda Arhiva educationala Marime 2.01 kb
#include <stdio.h>
#include <string.h>

int muchii[1000010];
int degree[100010];
char level[100010];
int Q[100010];

void BFS(int s)
{
    memset(level, 0xFF, sizeof level);

    int t, qs = qe = 0;

    level[s] = 0;

    Q[qe++] = s;

    while(qs < qe)
    {
        t = Q[qs++];

        for(int it = degree[t], tar = degree[t + 1], v; it != tar; ++it)
        {
            v = muchii[it];

            if(level[v] >= 0) continue;

            level[v] = level[t] + 1;

            Q[qe++] = v;
        }
    }
}

char buffer[20000000]; int p = -1;

__attribute__((always_inline)) int get_int()
{
    int number = 0;

    for(++p; buffer[p] > 47 && buffer[p] < 58; ++p)
    {
        number = number * 10 + buffer[p] - 48;
    }

    return number;
}

__attribute__((always_inline)) void put_int(int x)
{
    if(x > 9)
    {
        buffer[++p] = x / 10 + 48;

        buffer[++p] = x % 10 + 48;

        buffer[++p] = 32;

        return;
    }

    if(x == -1)
    {
        buffer[++p] = 45;

        buffer[++p] = 49;

        buffer[++p] = 32;

        return;
    }

    buffer[++p] = x + 48;

    buffer[++p] = 32;
}

int main()
{
    freopen("bfs.in", "r", stdin);
    freopen("bfs.out", "w", stdout);

    fread(buffer, 1, 20000000, stdin);

    int N, M, start, u, v;

    N = get_int();

    M = get_int();

    start = get_int();

    for(int i = 0; i < M; ++i)
    {
        u = get_int();

        v = get_int();

        ++degree[u];
    }

    for(int i = 1; i <= N; ++i)
    {
        degree[i] += degree[i - 1];
    }

    degree[N + 1] = M;

    p = -1;

    N = get_int();

    M = get_int();

    start = get_int();

    for(int i = 0; i < M; ++i)
    {
        u = get_int();

        v = get_int();

        muchii[--degree[u]] = v;
    }

    BFS(start);

    p = -1;

    for(int i = 1; i <= N; ++i)
    {
        put_int(level[i]);
    }

    fwrite(buffer, 1, p, stdout);

    return 0;
}