Compilare: main.cpp: In function 'int main()': main.cpp:21:34: warning: suggest parentheses around '&&' within '||' [-Wparentheses] if(!stk.empty() && ~~~~~~~~~~~~~~~~ stk.top() == '(' && c == ')' || ~~~~~~~~~~~~~~~~~^~~~~~~~~~~ main.cpp:23:34: warning: suggest parentheses around '&&' within '||' [-Wparentheses] stk.top() == '{' && c == '}' ) ~~~~~~~~~~~~~~~~~^~~~~~~~~~~ main.cpp:39:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] if(stk.size() == sters_poz) ~~~~~~~~~~~^~~~~~~~~~~~