Remove characters from alphanumeric string
#include<iostream>
#include<string>
using namespace std;
int main()
{
int t;
cin >> t;
while(t--){
string s, result = "";
cin >> s;
int len = s.size();
int pos = 0;
for(int i=0; i<len; i++){
if(s[i] >= '0' && s[i] <= '9')
result += s[i];
}
result += '\0';
cout << result <<endl;
}
return 0;
}