uva10763

题意：可以想象成数字的交换，然后最后判断是否有相换的数字是否有在换回来

思路:如果匹配的話那麼兩邊的輸入排序後一定是一致的

代碼:

#include<cstdio>#include<algorithm>using namespace std;const int N = 500005;int n, n1[N], n2[N];int main() {int i;while(scanf("%d", &n) && n) {bool flag = true;for(i=0; i<n; i++) {scanf("%d %d", &n1[i], &n2[i]);}if(n % 2 != 0) {flag = false;printf("NO\n");continue;}sort(n1, n1+n);sort(n2, n2+n);for(i=0; i<n; i++) {if(n1[i] != n2[i]) {printf("NO\n");flag = false;break;}}if(flag) printf("YES\n");}return 0;}