Given a string containing just the characters '('
, ')'
, '{'
, '}'
, '['
and ']'
, determine if the input string is valid.
The brackets must close in the correct order, "()"
and "()[]{}"
are all valid but "(]"
and "([)]"
are not.
#include#include #include #include using namespace std; bool isValid(string s) { if (s.empty()) return true; stack CharStack; for (int i = 0; i != s.size();++i){ if (s[i] == '(' || s[i] == '{' || s[i] == '[') CharStack.push(s[i]); else { if (CharStack.empty()) return false; switch (s[i]) { case ')': if (CharStack.top() == '(') CharStack.pop(); else return false; break; case ']': if (CharStack.top() == '[') CharStack.pop(); else return false; break; case'}': if (CharStack.top() == '{') CharStack.pop(); else return false; break; default: break; } } } return CharStack.empty(); }