Why only test case 3 fails here?

#1

#include
using namespace std;
long long int replace0( long long int n){
long
long int r1 =0;
while(n){
long
long int digit = n%10;
if(digit == 0) {r1 = r110+ 5;
n/=10;}
else{
r1 = r110 + digit;
n/=10;

      }
      
 }
  long
  long int r2=0;
 while(r1){
      r2 = r2*10 + r1%10;
      r1/=10;
 }
 return r2;

}
int main() {
long long int a;
cin>>a;
cout<<replace0(a);
return 0;
}

#2

hi @rudragarg09006_4fa678534132a743 your doubt is not reaching TA please talk with team, BTW refer this for now

#include<bits/stdc++.h>
using namespace std;
int main() {
	string s;
	cin>>s;
	int n = s.length();
	for(int i=0;i<n;i++){
		if(s[i] == '0')s[i] = '5';
	}
	cout<<s<<endl;
}