Help me in solving UWCOI20A problem

My issue

include <stdio.h>

int main() {
// your code goes here
int t;
scanf(“%d”,&t);
while(t–)
{
int n;
scanf(“%d”,&n);
int a[n];
for(int i =0;i < n;i++)
{
scanf(“%d”,&a[i]);
}
int max = a[0];
for(int i =0;i<n;i++)
{
if(max<a[i])
{
max = a[i];
}

    }
    printf("%d",max);
    
}

}
what is wrong in above code why it is saying “Failed on a Hidden Case”

My code

#include <stdio.h>

int main() {
	// your code goes here
	int t;
	scanf("%d",&t);
	while(t--)
	{
	    int n;
	    scanf("%d",&n);
	    int a[n];
	    for(int i =0;i < n;i++)
	    {
	        scanf("%d",&a[i]);
	    }
	    int max = a[0];
	    for(int i =0;i<n;i++)
	    {
	        if(max<a[i])
	        {
	            max = a[i];
	        }
	        
	        
	    }
	    printf("%d",max);
	    
	}

}


Learning course: Data Structures & Algorithms using C
Problem Link: Find maximum in an Array in Data Structures & Algorithms using C