PAT/PATAdvanced/1013.c

#include <stdio.h>

#define MAX 1000

void DFS(int v, int known[], int G[][MAX])
{
	known[v] = 1;
	for (int i = 0; i < MAX; i++)
		if ((G[v][i] || G[i][v]) && !known[i])
			DFS(i, known, G);
}

int main()
{
	int N, M, K;
	scanf("%d %d %d", &N, &M, &K);

	int Graph[MAX][MAX] = {{0}};

	int city1, city2;
	for (int i = 0; i < M; i++) {
		scanf("%d %d", &city1, &city2);
		Graph[city1][city2] = 1;
	}

	for (int i = 0; i < K; i++) {
		int known[MAX] = {0}, lostcity, count = 0;
		scanf("%d", &lostcity);

		known[lostcity] = 1;
		for (int i = 1; i <= N; i++)
			if (!known[i]) {
				DFS(i, known, Graph);
				count++;
			}
		printf("%d\n", count - 1);
	}
}