Compilare: main.cpp: In function 'void recur()': main.cpp:21:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(idx < s.size()){ ~~~~^~~~~~~~~~ main.cpp: In function 'void ifix()': main.cpp:41:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for(int i = 0; i < s.size(); i++){ ~~^~~~~~~~~~ main.cpp: In function 'int main()': main.cpp:59:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while(idx < s.size()){ ~~~~^~~~~~~~~~