Compilare: main.cpp: In function 'int debug(std::__cxx11::string)': main.cpp:14:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (nr < s.length() and ch == s[nr]) { ~~~^~~~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:34:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (x != aux.length()) { ~~^~~~~~~~~~~~~~~ main.cpp:40:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < chr.size(); ++i) { ~~^~~~~~~~~~~~ main.cpp:41:25: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = i + 1; j < chr.size(); ++j) { ~~^~~~~~~~~~~~ main.cpp:44:10: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (x != str[chr[j]].length() + 1) { ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~ main.cpp:49:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < chr.size(); ++i) { ~~^~~~~~~~~~~~ main.cpp:58:11: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if (x == prf.length() + 1 + str[chr[md]].length()) { ~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~