JavaScript循环神秘地更新字符串的值

Question

我构建了一个函数，它根据一些输入返回 "YES" 或 "NO"。 输入是一串应该平​​衡的括号。

例子:

平衡 - { [ ( ) ] }
非平衡 - { [ ( ] ) }

该函数为此调用返回 undefined。

isBalanced('{[(])}');

厌倦了调试。我确定循环内部有问题。

function isBalanced(s) {
    let brackets = s.split('');
    let balanced = "YES";
    const closedBrackets = ')]}';
    const bracketCompliment = {
        '(' : ')',
        '[' : ']',
        '{' : '}'
    };
    for(let idx = 0; idx < brackets.length; idx++){
        const item = brackets.splice(0, 1)[0];
        if(closedBrackets.includes(item)){
            balanced = "NO";   
            return;
        }
        const closeIdx = brackets.indexOf(bracketCompliment[item]);
        const remainder = closeIdx % 2;
        if(closeIdx === -1 || remainder !== 0){
            balanced = "NO";
            return;
        } else{
            brackets.splice(closeIdx, 1);
        }
    }
    return balanced;
}

Answer 1

你应该return balanced; 而不是return;

function isBalanced(s) {
  let brackets = s.split('');

  const closedBrackets = ')]}';

  const bracketCompliment = {
    '(': ')',
    '[': ']',
    '{': '}',
  };

  for (let idx = 0; idx < brackets.length; idx += 1) {
    const item = brackets.splice(0, 1)[0];

    if (closedBrackets.includes(item)) {
      return 'NO';
    }

    const closeIdx = brackets.indexOf(bracketCompliment[item]);

    if (closeIdx === -1 || closeIdx % 2 !== 0) {
      return 'NO';
    }
    
    brackets.splice(closeIdx, 1);
  }

  return 'YES';
}

console.log(isBalanced('{[(])}'));
console.log(isBalanced('{()}'));