fork download
copy 
  1. #define _CRT_SECURE_NO_WARNINGS
  2. #include <iostream>
  3. #include<bits/stdc++.h>
  4. #define ll long long
  5. #include<algorithm>
  6. #include<deque>
  7. #include<stack>
  8. #include<queue>
  9. using namespace std;
  10. int main(){
  11.   std::ios_base::sync_with_stdio(0);
  12.   cin.tie(NULL);
  13.   cout.tie(NULL);
  14.   int n;cin>>n;
  15.   int a[n];
  16.   deque<int> q2;
  17.   deque<int>q3;
  18.   for(int i=1;i<=n;i++){
  19.     cin>>a[i];//1 3 5 4 2
  20.     q3.push_back(a[i]);
  21.   }
  22.   int j=0;
  23.   for(int i=1;i<=n;i++){
  24.     if(a[j]==i+1){j++;q3.pop_front();}
  25.     else q2.push_front(i);
  26.   }
  27.   //for(int i=0;i<q3.size();i++)cout<<q3[i]<<' ';// 4 2
  28.   //cout<<"\n";
  29.   //for(int i=0;i<q2.size();i++)cout<<q2[i]<<' ';
  30.   for(int i=1;i<=q2.size();i++){
  31.       if(q2[i]!=q3[i]){cout<<"NO\n";return 0;}
  32.   }
  33.   cout<<"YES\n";
  34.  return 0;}
Success #stdin #stdout 0s 5248KB
comments (?)
stdin
copy 
Standard input is empty
stdout
copy 
NO
https://ideone.com/IjKcrI
language:
C++14 (gcc 8.3)
created:
2 years ago
visibility:
public

Share or Embed source code

Discover > Sphere Engine API

The brand new service which powers Ideone!

Discover > IDE Widget

Widget for compiling and running the source code in a web browser!