Compilare: main.cpp: In function 'int findMaxLen(std::__cxx11::string)': main.cpp:14:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare] for (int i = 0; i < str.length(); i++) ~~^~~~~~~~~~~~~~ main.cpp:20:41: warning: suggest parentheses around '&&' within '||' [-Wparentheses] if (str[stack.top()] == '(' && str[i] == ')' || str[stack.top()] == '[' && str[i] == ']' || str[stack.top()] == '{' && str[i] == '}') main.cpp:20:129: warning: suggest parentheses around '&&' within '||' [-Wparentheses] if (str[stack.top()] == '(' && str[i] == ')' || str[stack.top()] == '[' && str[i] == ']' || str[stack.top()] == '{' && str[i] == '}')