An array is given of n length, and we need to calculate the next greater element for each element in given array. If next greater element is not available in given array then we need to fill ‘_’ at that index place.

smallest greatest element.c

#include <stdio.h>

int main()
{
    int i,j,c,n,min,flag=0,d=0;
    scanf("%d",&n); //scanning the number of element in array.
    int a[n],b[n];
    for(i=0;i<n;i++)
    {
        scanf("%d",&a[i]);   // User enters array.
    }
    
    for(i=0;i<n;i++) 
    {
        min=0;
        for(j=0;j<n;j++) 
        {
            if((a[j]-a[i])<min&&(a[j]-a[i])>0)
            {
                min=a[j]-a[i];
                c=a[j];
                flag=1;
            }
        }
        if(flag=1)
        {
            b[d]=c;
            d++;
        }
        else
        {
            b[d]='_';
            d++;
        }
    }
    for(i=0;i<n;i++)
    {
        printf("%d",b[i]);
    }
    return 0;
}

It's still not working, Have to find the problem