Backtracking simple problem

1

What happens if I uncomment the commented line? Why are the outputs different?

using namespace std;

void permute_util (string s, int l, int r) {
  if (l==r) cout << s << endl;
  else {
    for (int i=l;i<=r;i++) {
      swap(s[l],s[i]);
      permute_util(s,l+1,r);
     // swap(s[l],s[i]);
    }
  }
}

void permute (string s) {
  permute_util(s,0,s.length()-1);
}

int main() {
  string s;
  cin >> s;
  permute(s);
  return 0;
}
2

They will be different because it allow the next branch of the tree to get the same value, as if it was untouched.