(BOJ, 5052) 전화번호 목록

트라이 기본 연습 문제

#define _CRT_SECURE_NO_WARNINGS
#include <stdio.h>
#include <malloc.h>

struct tree {
	int flag;
	struct tree* child[10];
}root;

int main() {
	int t, N, ans;
	char val[11];
	scanf("%d\n", &t);
	for (int test_case = 1; test_case <= t; test_case++) {
		scanf("%d\n", &N);
		for (int i = 0; i < 10; i++) {
			root.child[i] = NULL;
		}
		ans = 1;
		for (int i = 0; i < N; i++) {
			scanf("%s", &val);
			if (ans == 1) {
				struct tree* t = &root;
				for (int j = 0; val[j]; j++) {
					if (t->child[val[j] - '0'] == NULL) {
						t->child[val[j] - '0'] = (struct tree*)calloc(1,sizeof(struct tree));
						t = t->child[val[j] - '0'];
					}
					else {
						t = t->child[val[j] - '0'];
						if (val[j + 1] == 0) {
							ans = 0;
							break;
						}
					}
					if (t->flag == 1) {
						ans = 0;
						break;
					}
					else if (val[j + 1] == 0) {
						t->flag = 1;
					}
				}
			}
		}
		if (ans) printf("YES\n");
		else printf("NO\n");
	}
	return 0;
}