#include <stdio.h>
#include <stdlib.h>

#define VISITED 1
#define UNVISITED 0

typedef struct bfsarrray{

    int level;
    int node;
}BfsArray;

typedef struct node{

    int number_of_neighbours;
    int *neighbours;
    int *costs;

}AdjacencyList;

//calloc, realloc, malloc
//callocul este malloc cu initializare de 0 in plus
// int *a = malloc int *a = calloc 0 0 0 0 0 0

void addNeighbour(AdjacencyList **list, int node, int neighbour, int cost)
{
    if ((*list)[node].number_of_neighbours == 0)
    {
        (*list)[node].neighbours = (int *) calloc(1, sizeof(int));
        (*list)[node].costs = (int *) calloc(1, sizeof(int));
        (*list)[node].number_of_neighbours ++;
        (*list)[node].neighbours[(*list)[node].number_of_neighbours - 1] = neighbour;
        (*list)[node].costs[(*list)[node].number_of_neighbours - 1] = cost;

    }
    else
    {
        (*list)[node].number_of_neighbours ++;
        (*list)[node].neighbours = (int *) realloc((*list)[node].neighbours, (*list)[node].number_of_neighbours * sizeof(int));
        (*list)[node].costs = (int *) realloc((*list)[node].costs, (*list)[node].number_of_neighbours * sizeof(int));
        
        (*list)[node].neighbours[(*list)[node].number_of_neighbours - 1] = neighbour;
        (*list)[node].costs[(*list)[node].number_of_neighbours - 1] = cost;
    }
}

void DFS(AdjacencyList *list, int *visited, int currentNode)
{
    visited[currentNode] = VISITED;

    printf("%d \n", currentNode);

    for( int i = 0; i < list[currentNode].number_of_neighbours; i++)
    {
        if(visited[list[currentNode].neighbours[i]] == UNVISITED)
        {
            DFS(list, visited, list[currentNode].neighbours[i]);
        }
    }

}

void BFS(AdjacencyList *list, int numar_noduri, int nodStart)
{
    int *visited = (int *) calloc(numar_noduri + 1, sizeof(int));
    int *levels = (int *) calloc(numar_noduri + 1, sizeof(int));
    int startNode = nodStart;
    BfsArray *bfsarray = (BfsArray*)calloc(numar_noduri, sizeof(BfsArray));
    int currentPosition = 0;
    int numarNoduri = 0;
    bfsarray[0].node = startNode;
    bfsarray[0].level = 0;
    numarNoduri++;
    visited[startNode]=VISITED;
    while(currentPosition < numar_noduri)
    {
        for( int i = 0; i < list[bfsarray[currentPosition].node].number_of_neighbours; i++)
        {
            if(visited[list[bfsarray[currentPosition].node].neighbours[i]] == UNVISITED)
            {
                bfsarray[numarNoduri].node = list[bfsarray[currentPosition].node].neighbours[i];
                bfsarray[numarNoduri].level = bfsarray[currentPosition].level + 1;
                levels[bfsarray[numarNoduri].node] = bfsarray[numarNoduri].level;
                visited[list[bfsarray[currentPosition].node].neighbours[i]] = VISITED;
                numarNoduri++;
            }
        }
        currentPosition++;
    }    

    FILE *write = fopen("bfs.out","w");
    for(int i = 1; i <= numar_noduri; i++)
    {
        if(levels[i] == 0 && i != startNode)
            fprintf(write, "-1 ");
        else
            fprintf(write, "%d ", levels[i]);
        
    }

    free(bfsarray);
    free(visited);
}

void destroyAdjacencyList(AdjacencyList **list, int number_of_nodes)
{
    for(int i = 0; i <= number_of_nodes; i++)
    {
        if ((*list)[i].number_of_neighbours > 0)
        {
            free((*list)[i].neighbours);
            free((*list)[i].costs);
        }
    }
    free(*list);
}

int main()
{
    int numar_noduri, numar_muchii, startNode, x, y;
    
    FILE *read = fopen("bfs.in", "r");
    
    fscanf(read,"%d%d%d", &numar_noduri, &numar_muchii, &startNode);
    AdjacencyList * list = (AdjacencyList *) calloc(numar_noduri + 1, sizeof(AdjacencyList));

    for(int i = 0; i < numar_muchii; i++)
    {
        fscanf(read, "%d%d", &x, &y);
        addNeighbour(&list, x, y, 0);
    
    }

    BFS(list, numar_noduri, startNode);
    destroyAdjacencyList(&list, numar_noduri); 
    return 0;
}