数组排序

快速排序思绪

        Array.prototype.quickSortTwoPointers = function () {
            var sort = function (arr, startIdx, endIdx) { 
                if(startIdx >= endIdx) return;
                var left = startIdx,
                    right = endIdx,
                    pivot = arr[startIdx];
                while (left < right) {
                    while (left < right && arr[right] > pivot) {
                        right--
                    }
                    while (left < right && arr[left] <= pivot) {
                        left++
                    }
                    if (left < right) {
                        var temp = arr[left];
                        arr[left] = arr[right];
                        arr[right] = temp
                    }
                }
                if (left >= right) {
                    arr[startIdx] = arr[left]
                    arr[left] = pivot;
                    sort(arr, startIdx, left);
                    sort(arr, left + 1, arr.length -1);
                }
            }
            sort(this, 0, this.length -1);
            return this
        }