Binary Search

#include <cstdio>
int main(){
    int n;
    printf("Input array size: ");
    scanf("%d",&n);
    int a[n],f;
    printf("Input the array values 1 by 1:\n");
    for (int i=0; i<n; i++) scanf("%d",&a[i]);
    printf("Input the Search value: ");
    scanf("%d",&f);
    ///Binary search start.
    int l=0,r=n-1,m;
    while(l<=r){
        m=l+(r-1/2);
        if (a[m]==f)
            return!printf("Found at %d no index\n",m);
        else if (a[m]>n) r=m-1;
        else l=m+1;
    }
    printf("The value not found\n");
    return 0;
}