Target Sum Pair

I tried this and afterwards saw that in the hint same approach is there but still only 1 test case passed why?
But compiled successfully

using namespace std;
int main() {

int n;

cin>>n;
int arr[n];

for(int i=0;i<n;i++)

{

cin>>arr[i];

}

int target;

cin>>target;

sort(arr,arr+n);

int s=0;

int e=n-1;

int sum=0;

while(s<=e){

  sum=s+e;

  if(target==sum){
	  cout<<s<<" and "<<e<<endl;
	  s++;
	  e--;
  }
  else if(target>sum){
	  s++;
  }
  else{
	  e--;
  }

}

return 0;

}

sum=arr[s]+arr[e]
also

arr[s] and arr[e] instead of s and e again