/in/foo.cc: In function 'int main()':
/in/foo.cc:16:29: error: 'strlen' was not declared in this scope
  int num_tar = strlen(target);
                             ^
/in/foo.cc:25:8: warning: suggest explicit braces to avoid ambiguous 'else' [-Wparentheses]
     if (*p == target[i])
        ^