HDU 1233 Prim

prim水题:

#include <cstdio>
#include <cstring>

#define LEN 101
#define MMAX 9999999

int map[LEN][LEN];

int prime(int s, int city) {
	int dist[LEN], used[LEN];
	int i, j;
	int res = 0;
	memset(used, 0, sizeof(used));
	for(i = 1; i <= city; i++) {
		dist[i] = map[1][i];
	}
	used[1] = 1;
	for(i = 1; i < city; i++) {
		int imin, min;
		min = MMAX;
		for(j = 1; j <= city; j++) {
			if(min > dist[j] && used[j] == 0) {
				min = dist[j];
				imin = j;
			}
		}
		used[imin] = 1;
		if(min == MMAX) {
			return -1;
		}
		res += min;
		for(j = 1; j <= city; j++) {
			if(dist[j] > map[imin][j] && used[j] == 0) {
				dist[j] = map[imin][j];
			}
		}
	}
	return res;
}

int main() {
	int n;
	int s, e, len, tmp, res;
	while(scanf("%d", &n), n != 0) {
		int i, j;
		for(i = 0; i < LEN; i++) {
			for(j = 0; j < LEN; j++) {
				map[i][j] = MMAX;
			}
		}
		tmp = n*(n-1)/2;
		for(i = 0; i < tmp; i++) {
			scanf("%d%d%d", &s, &e, &len);
			map[s][e] = map[e][s] = len;
		}
		res = prime(1, n);
		printf("%d\n", res);
	}
	return 0;
}


 

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