JavaScriptAlgorithms/Tree/Heap.html at master · biaodigit/JavaScriptAlgorithms · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script src="../Sort/SortTestHelper.js"></script>
</head>
<body>
<script>
    // 最大堆
    class maxHeap {
        constructor() {
            this.data = [];
            this.head = 1;
        }

        initArr(arr) {
            this.data = arr;
            this.data.unshift(null);
            this.heaPiFy();
        }

        add(el) {
            if (!el) return
            this.data.push(el);
            this.shiftUp()
        }

        parentK(num) {
            return (num / 2) >> 1
        }

        shiftUp() {
            let count = this.data.length - 1;
            while (count > 1 && this.data[count] > this.data[this.parentK(count)]) {
                swap(this.data, count, this.parentK(count));
                count = this.parentK(count);
            }
        }

        shiftDown(k) {
            swap(this.data, 1, this.data.length - 1);
            this.data.pop();
            let count = this.data.length;
            while (2 * k < count) {
                let j = 2 * k;
                if (j + 1 <= count - 1 && this.data[j + 1] > this.data[j]) {
                    j += 1;
                }
                if (this.data[k] >= this.data[j]) return;

                swap(this.data, k, j);

                k = j;
            }
            console.log(this.data)
        }

        heaPiFyShiftDown(k) {
            let count = this.data.length;
            while (2 * k < this.data.length) {
                let j = 2 * k;
                if (j + 1 <= count - 1 && this.data[j + 1] > this.data[j]) {
                    j += 1;
                }
                if (this.data[k] >= this.data[j]) return

                swap(this.data, k, j);

                k = j;
            }
        }

        heaPiFy(arr) {
            for (let i = 0; i < arr.length; i++) {
                this.data[i + 1] = arr[i]
            }
            console.log(this.data)
            let n = this.data.length;
            for (let i = Math.floor(n / 2); i >= 1; i--) {
                this.heaPiFyShiftDown(i)
            }
            console.log(this.data)
        }

        //原地堆排序
        heapSort(arr) {
            this.data = this.data.concat(arr);
            let len = arr.length;
            for (let i = Math.floor((len - 1) / 2); i > 0; i--) {
                this._shiftDown(arr, len, i)
            }
            for (let i = len - 1; i > 0; i--) {
                swap(arr, 1, i);
                this._shiftDown(arr, i, 0);
            }
        }

        _shiftDown(arr, n, k) {
            while (2 * k < n) {
                let j = 2 * k;  //在此轮循环中，arr[k]和arr[j]交换位置
                if (j + 1 < n && arr[j + 1] > arr[j]) {
                    j += 1;
                }
                if (arr[k] >= arr[j]) {
                    break
                }
                swap(arr, k, j);
                k = j;
            }
        }

        findMax() {
            if (!this.data.length) {
                throw new TypeError("the data is null")
            }
            return this.data[this.head];
        }

        extraMax() {
            let res = this.findMax();
            this.shiftDown(this.head);
            return res
        }

        replace(e) {
            this.data[1] = e;
            this.heaPiFyShiftDown(this.head);
        }
    }


    new maxHeap().heaPiFy([3, 1, 5, 7, 2, 4, 9, 6, 10, 8]);
    // maxHeap.add(8.5)
    // maxHeap.shiftDown(1);
    // maxHeap.heapSort([9,8,7,6,5,4,3,2,1,0])

    // 最小堆
    class minHeap {
        constructor(arr) {
            this.data = arr.slice(0);
            this.data.unshift(null);
            this.count = this.data.length - 1;
            for (let i = this.count >> 1; i >= 1; i--) {
                this.shiftDown(i)
            }
        }

        shiftDown(k) {
            while (2 * k <= this.count) {
                let j = 2 * k;
                if (j + 1 <= this.count && this.data[j] > this.data[j + 1]) {
                    j += 1
                }
                if (this.data[k] > this.data[j]) {
                    [this.data[k], this.data[j]] = [this.data[j], this.data[k]]
                }
                k = j
            }
        }

        shiftUp(k) {
            while (k > 1 && this.data[k] < this.data[k >> 1]) {
                [this.data[k], this.data[k >> 1]] = [this.data[k >> 1], this.data[k]];
                k = k >> 1
            }
        }
    }
</script>
</body>
</html>