Foreign Exchange UVA

问题类型：排序，数组。

03pie’s solution for [UVA-10763]:
题目链接

#include<iostream>#include<cstdio>#include<map>#include<algorithm> const int maxn=500005; using namespace std;  int arr[maxn];  void swap(int a,int b){      int t=arr[a]; arr[a] = arr[b]; arr[b] = t;  } void init(){      for(int i=0; i<maxn; ++i)          arr[i] = i;  }  bool isOk(){      for(int i=0; i<maxn; ++i)          if(arr[i]!=i) return false;      return true;  }  int main() {//    freopen("F://inp.txt","r",stdin);    int n, i, a, b;      while(scanf("%d",&n), n){        init();          for(int i=0; i<n; ++i){              scanf("%d %d", &a, &b);              swap(a, b);          }         printf("%s\n",isOk()?"YES":"NO");    }      return 0;}