diff --git a/problems/0239.滑动窗口最大值.md b/problems/0239.滑动窗口最大值.md index d9788f63..adf3548c 100644 --- a/problems/0239.滑动窗口最大值.md +++ b/problems/0239.滑动窗口最大值.md @@ -395,30 +395,102 @@ func maxSlidingWindow(nums []int, k int) []int { Javascript: ```javascript +/** + * @param {number[]} nums + * @param {number} k + * @return {number[]} + */ var maxSlidingWindow = function (nums, k) { - // 队列数组(存放的是元素下标,为了取值方便) - const q = []; - // 结果数组 - const ans = []; - for (let i = 0; i < nums.length; i++) { - // 若队列不为空,且当前元素大于等于队尾所存下标的元素,则弹出队尾 - while (q.length && nums[i] >= nums[q[q.length - 1]]) { - q.pop(); + class MonoQueue { + queue; + constructor() { + this.queue = []; + } + enqueue(value) { + let back = this.queue[this.queue.length - 1]; + while (back !== undefined && back < value) { + this.queue.pop(); + back = this.queue[this.queue.length - 1]; + } + this.queue.push(value); + } + dequeue(value) { + let front = this.front(); + if (front === value) { + this.queue.shift(); + } + } + front() { + return this.queue[0]; + } } - // 入队当前元素下标 - q.push(i); - // 判断当前最大值(即队首元素)是否在窗口中,若不在便将其出队 - if (q[0] <= i - k) { - q.shift(); + let helperQueue = new MonoQueue(); + let i = 0, j = 0; + let resArr = []; + while (j < k) { + helperQueue.enqueue(nums[j++]); } - // 当达到窗口大小时便开始向结果中添加数据 - if (i >= k - 1) ans.push(nums[q[0]]); - } - return ans; + resArr.push(helperQueue.front()); + while (j < nums.length) { + helperQueue.enqueue(nums[j]); + helperQueue.dequeue(nums[i]); + resArr.push(helperQueue.front()); + i++, j++; + } + return resArr; +}; +``` + +TypeScript: + +```typescript +function maxSlidingWindow(nums: number[], k: number): number[] { + /** 单调递减队列 */ + class MonoQueue { + private queue: number[]; + constructor() { + this.queue = []; + }; + /** 入队:value如果大于队尾元素,则将队尾元素删除,直至队尾元素大于value,或者队列为空 */ + public enqueue(value: number): void { + let back: number | undefined = this.queue[this.queue.length - 1]; + while (back !== undefined && back < value) { + this.queue.pop(); + back = this.queue[this.queue.length - 1]; + } + this.queue.push(value); + }; + /** 出队:只有当队头元素等于value,才出队 */ + public dequeue(value: number): void { + let top: number | undefined = this.top(); + if (top !== undefined && top === value) { + this.queue.shift(); + } + } + public top(): number | undefined { + return this.queue[0]; + } + } + const helperQueue: MonoQueue = new MonoQueue(); + let i: number = 0, + j: number = 0; + let resArr: number[] = []; + while (j < k) { + helperQueue.enqueue(nums[j++]); + } + resArr.push(helperQueue.top()!); + while (j < nums.length) { + helperQueue.enqueue(nums[j]); + helperQueue.dequeue(nums[i]); + resArr.push(helperQueue.top()!); + j++, i++; + } + return resArr; }; ``` Swift: + ```Swift /// 双向链表 class DoublyListNode { diff --git a/problems/0435.无重叠区间.md b/problems/0435.无重叠区间.md index 118360bc..389443d1 100644 --- a/problems/0435.无重叠区间.md +++ b/problems/0435.无重叠区间.md @@ -183,28 +183,22 @@ public: ```java class Solution { public int eraseOverlapIntervals(int[][] intervals) { - if (intervals.length < 2) return 0; - - Arrays.sort(intervals, new Comparator() { - @Override - public int compare(int[] o1, int[] o2) { - if (o1[1] != o2[1]) { - return Integer.compare(o1[1],o2[1]); - } else { - return Integer.compare(o1[0],o2[0]); - } - } + Arrays.sort(intervals, (a, b) -> { + if (a[0] == a[0]) return a[1] - b[1]; + return a[0] - b[0]; }); - int count = 1; - int edge = intervals[0][1]; - for (int i = 1; i < intervals.length; i++) { - if (edge <= intervals[i][0]){ - count ++; //non overlap + 1 + int count = 0; + int edge = Integer.MIN_VALUE; + for (int i = 0; i < intervals.length; i++) { + if (edge <= intervals[i][0]) { edge = intervals[i][1]; + } else { + count++; } } - return intervals.length - count; + + return count; } } ``` diff --git a/problems/背包问题理论基础完全背包.md b/problems/背包问题理论基础完全背包.md index f79310b8..cea69c72 100644 --- a/problems/背包问题理论基础完全背包.md +++ b/problems/背包问题理论基础完全背包.md @@ -183,11 +183,9 @@ private static void testCompletePack(){ int[] value = {15, 20, 30}; int bagWeight = 4; int[] dp = new int[bagWeight + 1]; - for (int i = 0; i < weight.length; i++){ - for (int j = 1; j <= bagWeight; j++){ - if (j - weight[i] >= 0){ - dp[j] = Math.max(dp[j], dp[j - weight[i]] + value[i]); - } + for (int i = 0; i < weight.length; i++){ // 遍历物品 + for (int j = weight[i]; j <= bagWeight; j++){ // 遍历背包容量 + dp[j] = Math.max(dp[j], dp[j - weight[i]] + value[i]); } } for (int maxValue : dp){ @@ -201,8 +199,8 @@ private static void testCompletePackAnotherWay(){ int[] value = {15, 20, 30}; int bagWeight = 4; int[] dp = new int[bagWeight + 1]; - for (int i = 1; i <= bagWeight; i++){ - for (int j = 0; j < weight.length; j++){ + for (int i = 1; i <= bagWeight; i++){ // 遍历背包容量 + for (int j = 0; j < weight.length; j++){ // 遍历物品 if (i - weight[j] >= 0){ dp[i] = Math.max(dp[i], dp[i - weight[j]] + value[j]); }