func_code_string: #include <bits/stdc++.h>   using namespace std;   int main() {     int t;     cin >> t;     while (t-- > 0) {       char c[100005];       int n;       cin >> n;       string s0 =   ;       string sm =   ;       string s1 =   ;       bool flag0 = true;       int pos1 = -1;       int pos0 = -1;       for (int i = 1; i <= n; i++) {         cin >> c[i];         if (c[i] ==  1 ) {           if (flag0) flag0 = false;           if (pos1 == -1) pos1 = i;           s1 = s1 +  1 ;         } else {           if (flag0) s0 = s0 +  0 ;           s1 =   ;           pos0 = i;         }       }       if (pos1 != -1 && pos0 != -1 && pos0 > pos1) sm =  0 ;       string s = s0 + sm + s1;       cout << s << endl;     }   }   