https://leetcode.cn/problems/spiral-matrix-ii/submissions/589626378/
一次过
```js
var generateMatrix = function (n) {
const arr = new Array(n).fill(0).map(() => new Array(n).fill(0));
const fill = (x, y, len, def) => {
for (let index = x; index < len; index++) {
arr = def++;
}
def--;
for (let index = y; index < len; index++) {
arr = def++;
}
def--;
for (let index = len - 1; index >= x; index--) {
arr = def++;
}
def--;
for (let index = len - 1; index >= x+1; index--) {
arr = def++;
}
return def;
};
const layout = Math.ceil(n / 2);
let def = 1;
let len = n;
for (let index = 0; index < layout; index++) {
def = fill(index, index, len, def);
len--;
}
return arr
};
```
https://leetcode.cn/problems/text-justification/submissions/589723367/?envType=study-plan-v2&envId=top-interview-150
硬编码题，不喜欢这种
```js
var fullJustify = function (words, maxWidth) {
let stack = [];
let len = 0;
const ans = []
const handList = () => {
if(stack.length==1){
ans.push(stack+new Array(maxWidth-stack.length).fill(" ").join(''))
stack.pop()
len = 0;
return
}
const spaceNum = stack.length - 1;
const spaceWidth = Math.floor((maxWidth - len) / spaceNum)
let extraSpace = maxWidth - len - (spaceWidth * spaceNum)
let spaceWidthStr = new Array(spaceWidth).fill(" ").join('')
let str = ""
while (stack.length !== 0) {
str += stack.shift();
if (stack.length !== 0) {
str += spaceWidthStr
}
if (extraSpace !== 0) {
str += " "
extraSpace--
}
}
len = 0;
ans.push(str)
}
for (let index = 0; index < words.length; index++) {
const word = words;
if (len + word.length + stack.length > maxWidth) {
handList()
}
stack.push(word);
len += word.length
}
stack=
handList()
return ans
};
```
https://leetcode.cn/problems/populating-next-right-pointers-in-each-node-ii/submissions/589726283/?envType=study-plan-v2&envId=top-interview-150
层序递归
秒了
```js
var connect = function (root) {
if(root==null){
return null
}
let stack = []
stack.push(root);
right = null;
let nextStack = []
while (stack.length !== 0) {
let item = stack.pop()
item.next = right;
right = item;
item.right && nextStack.unshift(item.right);
item.left && nextStack.unshift(item.left);
if (stack.length == 0) {
stack = nextStack;
nextStack = [];
right = null;
}
}
return root
};
```
https://leetcode.cn/problems/split-the-array/submissions/589763029/
打卡题
```js
var isPossibleToSplit = function (nums) {
const cache = new Map();
const chache2 = new Map();
for (let index = 0; index < nums.length; index++) {
const num = nums;
if (!cache.has(num)) {
cache.set(num, 1);
} else if (!chache2.has(num)) {
chache2.set(num, 1);
}else{
return false
}
}
return true
};
```
https://leetcode.cn/problems/substring-with-concatenation-of-all-words/submissions/589783956/?envType=study-plan-v2&envId=top-interview-150
看的答案
这个题做的还是挺有意思的
```js
var findSubstring = function (s, words) {
const wordsCount = words.length;
const len = words.length;
const cache = new Map();
const ans = [];
for (const word of words) {
cache.set(word, (cache.get(word) ?? 0) + 1);
}
for (let index = 0; index < len; index++) {
const temp = new Map();
let pos = index;
while (pos + len <= s.length) {
const str = s.substring(pos, pos + len);
pos += len;
temp.set(str, (temp.get(str) ?? 0) + 1);
if (pos - index > len * wordsCount) {
const pre = s.substring(
pos - len * (wordsCount+1),
pos - len * (wordsCount )
);
if (temp.get(pre) == 1) {
temp.delete(pre);
} else {
temp.set(pre, (temp.get(pre) ?? 0) - 1);
}
if (temp.get(pre) !== cache.get(pre)) {
continue;
}
}
if (temp.get(str) !== cache.get(str)) {
continue;
}
let isSame = true;
for (let of cache) {
if (temp.get(key) !== value) {
isSame = false;
break;
}
}
if (isSame) {
ans.push(pos - len * wordsCount);
}
}
}
return ans
};
```
https://leetcode.cn/problems/n-ary-tree-level-order-traversal/submissions/589786867/
N叉树，length扣半天
```js
var levelOrder = function (root) {
if(root==null){
return []
}
const stack = [];
stack.push(root);
const ans = [];
while (stack.length !== 0) {
const num = stack.length;
const list = [];
for (let index = 0; index < num; index++) {
const item = stack.shift();
for (let indey = 0; indey < item.children.length; indey++) {
const children = item.children;
stack.push(children);
}
list.push(item.val);
}
ans.push(list);
}
return ans
};
```
https://leetcode.cn/problems/find-k-pairs-with-smallest-sums/submissions/589795796/?envType=study-plan-v2&envId=top-interview-150
堆问题，但是没处理hash，没有什么思路，一会看一眼题解
```js
class MaxHeap {
constructor(comparator = (a, b) => a - b) {
this.heap = [];
this.comparator = comparator;
}
// 获取父节点索引
parentIndex(index) {
return Math.floor((index - 1) / 2);
}
// 获取左子节点索引
leftChildIndex(index) {
return 2 * index + 1;
}
// 获取右子节点索引
rightChildIndex(index) {
return 2 * index + 2;
}
// 交换两个节点
swap(index1, index2) {
const temp = this.heap;
this.heap = this.heap;
this.heap = temp;
}
// 向堆中插入元素
insert(value) {
this.heap.push(value);
this.heapifyUp();
}
// 堆化上移
heapifyUp() {
let index = this.heap.length - 1;
while (
index > 0 &&
this.comparator(this.heap, this.heap) > 0
) {
this.swap(index, this.parentIndex(index));
index = this.parentIndex(index);
}
}
// 移除堆顶元素
extractMax() {
if (this.heap.length === 0) return null;
if (this.heap.length === 1) return this.heap.pop();
const max = this.heap;
this.heap = this.heap.pop();
this.heapifyDown(0);
return max;
}
// 堆化下移
heapifyDown(index) {
let largest = index;
const left = this.leftChildIndex(index);
const right = this.rightChildIndex(index);
if (
left < this.heap.length &&
this.comparator(this.heap, this.heap) > 0
) {
largest = left;
}
if (
right < this.heap.length &&
this.comparator(this.heap, this.heap) > 0
) {
largest = right;
}
if (largest !== index) {
this.swap(index, largest);
this.heapifyDown(largest);
}
}
// 获取堆顶元素
peek() {
return this.heap.length > 0 ? this.heap : null;
}
// 获取堆的大小
size() {
return this.heap.length;
}
}
/**
* @param {number[]} nums1
* @param {number[]} nums2
* @param {number} k
* @Return {number[][]}
*/
var kSmallestPairs = function (nums1, nums2, k) {
this.maxHeap = new MaxHeap((a, b) => {
const total1 = nums1 + nums2;
const total2 = nums1 + nums2;
return total2 - total1;
}); // 默认比较器，构建最大堆
const cache = new Map();
this.maxHeap.insert({
pos1: 0,
pos2: 0,
});
const ans = [];
for (let index = 0; index < k; index++) {
const node = this.maxHeap.extractMax();
const tag = `${node.pos1} ${node.pos2}`;
if (cache.has(tag)) {
index--;
continue;
}
cache.set(tag,1)
ans.push(, nums2]);
if (node.pos1 + 1 < nums1.length && node.pos2 < nums2.length) {
this.maxHeap.insert({
pos1: node.pos1 + 1,
pos2: node.pos2,
});
}
if (node.pos2 + 1 < nums2.length && node.pos1 < nums1.length) {
this.maxHeap.insert({
pos1: node.pos1,
pos2: node.pos2 + 1,
});
}
}
return ans;
};
```
https://leetcode.cn/problems/bitwise-and-of-numbers-range/submissions/589797664/?envType=study-plan-v2&envId=top-interview-150
看了一眼答案
规律题太抽象了...
```js
var rangeBitwiseAnd = function (left, right) {
const num = 32 - Math.clz32(left ^ right);
return left&(~((1<<num)-1))
};
```
https://leetcode.cn/problems/reverse-bits/description/?envType=study-plan-v2&envId=top-interview-150
不知道为什么t>>> 0结果就对了
感觉有截断什么的
```js
var reverseBits = function (n) {
let result = 0;
for (let index = 0; index < 32; index++) {
if (n & (1 << index)) {
result = result | (1 << (31 - index));
}
}
return result>>> 0;
};
```
https://leetcode.cn/problems/making-file-names-unique/submissions/589829921/
主要最后有一个卡测例
```js
var getFolderNames = function (names) {
const cache = new Map();
const jump = new Map()
const ans = []
for (let index = 0; index < names.length; index++) {
let name = names;
if (cache.has(name)) {
let pos = (jump.get(name) ?? 0) + 1
let checkName = name + `(${pos})`
while (cache.has(checkName)) {
pos++;
checkName = name + `(${pos})`
}
jump.set(name, pos)
cache.set(checkName, true)
ans.push(checkName)
} else {
cache.set(name, true)
ans.push(name)
}
}
return ans
};
```