Not being able to enter input during runtime

Question

When I compile the code with inputs then it works fine. But when I want to run it with user input, it just doesn't take in inputs. It doesn't give any error.

// kefaa and first steps
// 2 2 1 3 4 1

#include <bits/stdc++.h>
using namespace std;

int main(){
    int n, a[n], counter=0, maxIncr=0;
    cin >> n;
    cin.sync(); 
    for(int i = 0; i < n; ++i){
        cin >> a[i];
    }
    for(int i=0; i < n-1; ++i){
        if (a[i] <= a[i+1]){
            counter += 1;
            if(maxIncr<counter)
                maxIncr=counter;
        }else{
            counter=1;
        }
    }
    cout << maxIncr;
    return 0;
}

`int a[n]` is not standard C++ *and* invokes *undefined behavior* as you haven't initialized `n` yet — UnholySheep, May 25 '20 at 07:30
Best not to use [cin.sync](https://stackoverflow.com/questions/10585392/the-difference-between-cin-ignore-and-cin-sync) — Alan Birtles, May 25 '20 at 07:54

score 1 · Accepted Answer · edited May 25 '20 at 07:43

1

First of all read this about your include and why we don't include like this.

Second, if you want your program to run:

  int n; 
  cin >> n;
  int a[n], counter=0, maxIncr=0;

what you have it like @UnholySheep wrote to you, you initialize a[n] when n has not yet been assigne a value.

edited May 25 '20 at 07:43

Jabberwocky

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answered May 25 '20 at 07:35

yaodav

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Not being able to enter input during runtime

1 Answers1