[UVa] 10763 Foreign Exchange.cpp

#include <cstdio>
#include <algorithm>
using namespace std;
int N;
int origin[500001], target[500001];
int main()
{
    while (scanf("%d",&N)){
        if (!N) break;
        for (int i=0; i<N; i++)
            scanf("%d %d",&origin[i],&target[i]);
        if (N % 2) {
            printf("NO\n");
            continue;
        }
        sort(origin, origin+N, cmp);
        sort(target, target+N, cmp);
        
        bool yes = 1;
        for (int i=0; i<N; i++)
            if (origin[i] != target[i])
                yes = 0;
        printf("%s\n", yes ? "YES" : "NO");
    }
    return 0;
}