0020_Valid_Parentheses.go

package leetcode

func validParentheses(s string) bool {
	if len(s) == 0 {
		return true
	}
	stack := make([]rune, 0)
	for _, v := range s {
		if v == '(' || v == '[' || v == '{' {
			stack = append(stack, v)
		} else if (v == ')' && len(stack) > 0 && stack[len(stack)-1] == '(') ||
			(v == ']' && len(stack) > 0 && stack[len(stack)-1] == '[') ||
			(v == '}' && len(stack) > 0 && stack[len(stack)-1] == '{') {
			stack = stack[:len(stack)-1]
		} else {
			return false
		}
	}
	return len(stack) == 0
}