Cod sursa(job #1561232)

Utilizator Mihai22eMihai Ionut Enache Mihai22e Data 3 ianuarie 2016 20:01:46
Problema BFS - Parcurgere in latime Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.29 kb
#include <vector>

#include <cstdio>
using namespace std;

const int MAX_N = 100002;

template <class T>
class ListNode {
	public:
		ListNode *next;
		T val;
		
		ListNode() {
			next = NULL;
		}
};

template <class T>
class Queue {
		ListNode <T> *lo;
		ListNode <T> *hi;

	public:
		Queue() {
			lo = new ListNode <T>;
			hi = lo;
		}

		void popElement() {
			ListNode <T> *tmp = lo;

			lo = lo->next;
			delete tmp;
		}

		void pushElement(T x) {
			hi->next = new ListNode <T>;
			hi = hi->next;
			hi->val = x;
		}

		int getFront() {
			return lo->next->val;
		}

		bool isEmpty() {
			return lo == hi;
		}
};

int n, m, s;
int d[MAX_N];
vector <int> v[MAX_N];
Queue <int> q;

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

	scanf("%d %d %d", &n, &m, &s);
	for(int i = 1; i <= m; ++i) {
		int x, y;
		
		scanf("%d %d", &x, &y);
		v[x].push_back(y);
	}

	for(int i = 1; i <= n; ++i) {
		d[i] = -1;
	}

	d[s] = 0;
	q.pushElement(s);
	while(q.isEmpty() == false) {
		int x = q.getFront();
		q.popElement();
		
		for(int i = 0; i < (int) v[x].size(); ++i) {
			int y = v[x][i];
			
			if(d[y] == -1 || d[x] + 1 < d[y]) {
				d[y] = d[x] + 1;
				q.pushElement(y);
			}
		}
	}

	for(int i = 1; i <= n; ++i) {
		printf("%d ", d[i]);
	}
	
	fclose(stdin);
	fclose(stdout);
	
	return 0;
}