Selection Sort

/*
* 1: time complexity o(n^2)
* 2: good performance for items around 10-20: better than merge sort and quick sort
* 3: no extra space needed
* */
public class SelectSort {
    public static void main(String[] args) {
        int[] nums = {3, -3, 5, 1, 1, 2, -10};
        //this is the make sure no index out bound
        for (int i = 0; i < nums.length-1; i++) {
            /* left = 0, right =lenth - 1 = 6
            * round 1: i = 0, nums[i] = -3, from [-3, 5, 1, 1, 2, -10], the lowest index = 6
            * swap 3 and -10, output result = [-10, -3, 5, 1, 1, 2,3]
            * */
            int index = i ;
            for (int j = i+1; j < nums.length; j++) {
                if (nums[j]<nums[index]){
                    index  = j ;
                }
            }
            //when it comes to here, the index already point to the lowest num from the right(unsorted)
            //note, dont if the i is the lowest, dont need to swap with itself
            if (i != index){
                int temp = nums[i] ;
                nums[i] = nums[index] ;
                nums[index] = temp ;
            }
        }
        showNumber(nums);
    }

    public static void showNumber(int[] nums) {
        for (int i = 0; i < nums.length; i++) {
            System.out.println("nums[i]" + nums[i]);
        }
    }
}