Submission #6687560

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Source Code Expand

#include<iostream>
#include<algorithm>
#include<vector>
#include<queue>
#include<unordered_set>
#include<unordered_map>
using namespace std;
typedef long long ll;
#define mod 1000000007
#define mad(a,b) a=(a+b)%mod;
ll n,h[100010];
int main(){
  cin>>n;
  for(int i=0;i<n;i++)cin>>h[i];
  h[0]--;
  for(int i=1;i<n;i++){
    if(h[i-1]>h[i]){
      cout<<"No"<<endl;
      return 0;
    }
    if(h[i-1]==h[i])continue;
    h[i]--;
  }
  cout<<"Yes"<<endl;
  return 0;
}

Submission Info

Judge Result