SPOJ PROBLEM 95: STREET PARADE (STPAR)

Problem Link 

Done using stack 

Logic is to take an test array and make operations to make an series of 1,2,3,4...........
if possible!!!!

Code::

#include <iostream>
#include<stack>
#define MAX 1001
using namespace std;

int main() {
    int n;
    stack<int> s;      
    cin>>n;
    while(n!=0)
    {
    int arr[MAX]={0},test[MAX]={0};
    while(!s.empty())   s.pop();   // clear the stack
    for(int i=1;i<=n;i++)    cin>>arr[i];
    int j=0;
    int num=1;
    
     for(j=1;j<=n;j++)
    {
           if(arr[j]==num)      // checked in array if number is present
              {
                  test[num++]=arr[j];
                  continue;
              }
            while(!s.empty() && s.top()==num)  //checked at the top of stack if num is present
            {
                test[num++]=s.top();
                s.pop();
            }
            s.push(arr[j]);
    }
    while(s.size()!=0)         // making the stack empty at the last
    {
        test[num++]=s.top();
        s.pop();
    }
    int flag=0;
    for(int k=1;k<=n;k++)      // checking whether array can be modified in the way given 
    {
        //cout<<test[k];
        if(test[k]!=k)   {  flag=1;  break;  }
    }
    if(flag==0)  cout<<"yes"<<endl;
    else   cout<<"no"<<endl;
    cin>>n;
    }
    // your code goes here
    return 0;
}