Compilare: main.cpp: In function 'int main()': main.cpp:69:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < expression.size(); i++) { ~~^~~~~~~~~~~~~~~~~~~ main.cpp:73:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] while (i < expression.size() && expression[i] != ' ') { ~~^~~~~~~~~~~~~~~~~~~ main.cpp:112:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int j = 0; j < ascii[ch - 'A'].size(); j++) { ~~^~~~~~~~~~~~~~~~~~~~~~~~ main.cpp: In function 'bool expressionAND()': main.cpp:53:1: warning: control reaches end of non-void function [-Wreturn-type] } ^