## 选择排序 SelectSort * 空间复杂度：O(1) * 时间复杂度：O(n2) ## 思路描述 每一次选择数组中最小的值，放到最左边  ## 例子 ``` old:[13, 7, 4, 6, 9, 24, 12, 3, 5, 2] select=2,swap 2 to 13 0)[2, 7, 4, 6, 9, 24, 12, 3, 5, 13] select=3,swap 3 to 7 1)[2, 3, 4, 6, 9, 24, 12, 7, 5, 13] select=5,swap 5 to 6 3)[2, 3, 4, 5, 9, 24, 12, 7, 6, 13] select=6,swap 6 to 9 4)[2, 3, 4, 5, 6, 24, 12, 7, 9, 13] select=7,swap 7 to 24 5)[2, 3, 4, 5, 6, 7, 12, 24, 9, 13] select=9,swap 9 to 12 6)[2, 3, 4, 5, 6, 7, 9, 24, 12, 13] select=12,swap 12 to 24 7)[2, 3, 4, 5, 6, 7, 9, 12, 24, 13] select=13,swap 13 to 24 8)[2, 3, 4, 5, 6, 7, 9, 12, 13, 24] result:[2, 3, 4, 5, 6, 7, 9, 12, 13, 24] ``` ## java实现 ~~~ public class SelectSort { public static void main(String[] args) { int[] nums = {13,7,4,6,9,24,12,3,5,2}; System.out.println("old:"+ Arrays.toString(nums)); System.out.println("result:"+Arrays.toString(sort(nums))); } // 选择排序 public static int[] sort(int[] nums){ int select = 0; for(int i=0;i<nums.length;i++){ select = i; for(int j=i;j<nums.length;j++){ if(nums[j]<nums[select]){ select = j; } } if(select != i) { System.out.println("select="+nums[select]+",swap "+nums[select]+" to "+ nums[i]); swap(nums, i, select); System.out.println(i + ")" + Arrays.toString(nums)); } } return nums; } // 交换数组下标 public static void swap(int[] nums,int i,int j){ int temp = nums[i]; nums[i] = nums[j]; nums[j] = temp; } } ~~~