Compilare: main.cpp: In function 'int main()': main.cpp:34:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 1; i < s.length(); i++) { ~~^~~~~~~~~~~~ main.cpp:35:9: warning: unused variable 'cr' [-Wunused-variable] char cr = s[i]; ^~ main.cpp:67:22: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 1; j < s.size() - 1; j++) { ~~^~~~~~~~~~~~~~