GGCD

#include <stdio.h>

int gcd(int a, int b){
    return a==0?b:gcd(b%a,a);
}

void insertionSort(int arr[], int n){
   int key, j;
   for(int i=1;i<n;i++){
       key = arr[i];
       j = i-1;
       while (j>=0 && arr[j]>key){
           arr[j+1] = arr[j];
           j--;
       }
       arr[j+1] = key;
   }
}

int findGCD(int arr[], int n){
    int high=0;
    for(int i=n-1;i>=0;i--){
        for(int j=i-1;j>=0;j--){
            int temp = gcd(arr[i], arr[j]);
            if(arr[j]<high){
                break;
            }else if(temp>high){
                high = temp;
            }
        }
    }
    return high;
}

int main(){
    int tc;
    scanf("%d", &tc);
    for(int i=1;i<=tc;i++){
        int n, product=1, high=0, check;
        scanf("%d", &n);
        int data[n];
        for(int j=0;j<n;j++){
            scanf("%d", &data[j]);
        }
        insertionSort(data, n);
        printf("Case #%d: %d\n", i, findGCD(data, n));
    }
    return 0;
}