Compilare: user.cpp: In function ‘int main()’: user.cpp:17:5: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(s[i] == ')') ^ user.cpp:23:5: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(s[i] == ']') ^ user.cpp:29:5: warning: suggest explicit braces to avoid ambiguous ‘else’ [-Wparentheses] if(s[i] == '}') ^