Codeforces Round #436 (Div. 2) Make a Permutation!
#include#definepbpush_back#definempmake_pairusingnamespacestd;inta[200005];intvis[200005];//记录访问过几次boolvis1[200005];//记录是不是访问过intmain(){intn;scanf("%d",&n);memset(vis,0,sizeof(vis));memset(vis1,0,size