/in/foo.cc: In function 'int main()':
/in/foo.cc:28:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while (start < reversed.length() - 1 && reversed[start] == '0') {
            ~~~~~~^~~~~~~~~~~~~~~~~~~~~~~
/in/foo.cc:55:29: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         while (firstNonZero < minStr.length() && minStr[firstNonZero] == '0') {
                ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~
/in/foo.cc:58:26: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         if (firstNonZero < minStr.length() && firstNonZero > 0) {
             ~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~