104.111. 二叉树的最小/最大深度

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// 升级一下initTree的代码
const initTree = (inputList) => {
    const total = inputList.length;
    if(!inputList[0])return null;
    inputList[0] = new TreeNode(inputList[0]);
    inputList.forEach((el,index) => {
        let leftP = null;
        let rightP = null;
        if (!el) return;
        if (index*2+1 < total) {
            leftP = inputList[index*2+1]? new TreeNode(inputList[index*2+1]): null;
            inputList[index*2+1] = leftP;
        } 
        if (index*2+2 < total) {
            rightP = inputList[index*2+2]? new TreeNode(inputList[index*2+2]): null;
            inputList[index*2+2] = rightP;
        }
        inputList[index].left = leftP;
        inputList[index].right = rightP;
    });
    return inputList[0];
}

function TreeNode(val, left, right) {
    this.val = (val===undefined ? 0 : val)
    this.left = (left===undefined ? null : left)
    this.right = (right===undefined ? null : right)
}

/**
 * @param {TreeNode} root
 * @return {number}
 */
var maxDepth = function(root) {
    if(!root) return 0;
    const queue = [root];
    const depList = [];
    let levelNum = 0;
    while(queue.length) {
        const levelLen = queue.length;
        levelNum += 1;
        for(let i=0;i<levelLen;i++){
            const curNode = queue.pop();
            if (curNode.left) queue.unshift(curNode.left);
            if (curNode.right) queue.unshift(curNode.right);
            if (!curNode.left && !curNode.right) {
                depList.push(levelNum);
            }
        }
    }
    return Math.max(...depList);
};

/**
 * @param {TreeNode} root
 * @return {number}
 */
var minDepth = function(root) {
    if(!root) return 0;
    const queue = [root];
    const depList = [];
    let levelNum = 0;
    while(queue.length) {
        const levelLen = queue.length;
        levelNum += 1;
        for(let i=0;i<levelLen;i++){
            const curNode = queue.pop();
            if (curNode.left) queue.unshift(curNode.left);
            if (curNode.right) queue.unshift(curNode.right);
            if (!curNode.left && !curNode.right) {
                depList.push(levelNum);
            }
        }
    }
    return Math.min(...depList);
};

// 验证代码
(()=>{
    const input = [3,9,20,null,null,15,7];
    const root = initTree(input);
    console.log('root', root);
    const res = maxDepth(root);
    console.log('res', res);
})();