I am storing all digits in a vector, then reforming the reverse number.
#include<iostream>
#include<vector>
using namespace std;
int rev(int k) {
vector<int> A;
int m = 10;
while (k % m != k) {
A.push_back((k % m)/(m/10));
m *= 10;
}
A.push_back((k % m) / (m / 10));
int sum = 0;
int n = A.size();
for (int i = 0; i < n; i++) {
sum += A[i] * m;
m /= 10;
}
return sum/10;
}
int main() {
int t, p, q;
cin >> t;
for (int i = 0; i < t; i++) {
cin >> p >> q;
cout << rev(rev(p) + rev(q)) << "\n";
}
return 0;
}