Leetcode 32509：最长有效括号-斐波那契数

Posted 2021-12-18 hello，是翠花呀

最长有效括号

var longestValidParentheses = function(s) 
  if (!s) 
    return 0;
  

  let stack = [];
  let maxLen = 0;
  let start = 0

  for (let i = 0; i < s.length; i++) 
    if (s[i] === '(') 
      stack.push(i);

     else if (s[i] === ')') 
      // 如果stack为空
      if (!stack.length) 
        start = i + 1

       else 
        stack.pop();

        if (stack.length) 

          maxLen = Math.max(maxLen, i - stack[stack.length- 1])

         else 
          maxLen = Math.max(maxLen, i - start + 1)
        
      
      
    
  
  return maxLen
;

斐波那契数

var fib = function(n) 
  if (n === 0) 
    return 0;
  
  if (n === 1) 
    return 1;
  

  return fib(n - 1) + fib(n - 2);
;