View Compilation Error

0_0_38948959_12872.cpp: In function 'int dfs(int)':
0_0_38948959_12872.cpp:4:28: error: 's' was not declared in this scope
    4 |         for (int i = step; s[i] != 0 && s[i] != ')'; i++, step++) {
      |                            ^
0_0_38948959_12872.cpp:22:13: error: 's' was not declared in this scope
   22 |         if (s[step] == ')') return step;
      |             ^