四、排序

1. 冒泡排序

时间复杂度O(n²)

Array.prototype.bubbleSort = function () {
  for (let i = 0; i < this.length; i++) {
    for (let j = 0; j < this.length - 1 - i; j++) {
      if (this[j] > this[j + 1]) {
        const temp = this[j];
        this[j] = this[j + 1];
        this[j + 1] = temp;
      }
    }
  }
  return this;
};
const arr = [5, 4, 3, 2, 1];
console.log(arr.bubbleSort());

2. 选择排序

时间复杂度O(n²)

Array.prototype.selectionSort = function () {
  for (let i = 0; i < this.length - 1; i++) {
    let minIndex = i;
    for (let j = i; j < this.length; j++) {
      if (this[j] < this[minIndex]) {
        minIndex = j;
      }
    }
    if (minIndex !== i) {
      const temp = this[i];
      this[i] = this[minIndex];
      this[minIndex] = temp;
    }
  }
  return this;
};
const arr = [5, 4, 3, 2, 1];
console.log(arr.selectionSort());