Question

把數組所有的值為0的元素移到末尾

Given an array nums, write a function to move all 0's to the end of it while maintaining the relative order of the non-zero elements.
For example, given nums = [0, 1, 0, 3, 12], after calling your function, nums should be [1, 3, 12, 0, 0].
Note:
You must do this in-place without making a copy of the array.
Minimize the total number of operations.

Solutions

寫了個效率很低的

public class Solution {
    public void moveZeroes(int[] nums) {
        for (int i = 0; i < nums.length; i++) {
            if (nums[i] == 0) {
                for (int j = i + 1; j < nums.length; j++) {
                    if (nums[j] != 0) {
                        nums[i] = nums[j];
                        nums[j] = 0;
                        break;
                    }
                }
            }
        }
    }
}

效率高的不會寫，就去討論區研究了下

public class Solution {
  public void moveZeroes(int[] nums) {
  int index = 0; 
    for(int i = 0;i<nums.length;i++){ 
      if(nums[i] !=0){ 
        nums[index++] = nums[i];
      }
    }
 
    for(int i = index;i<nums.length;i++){
        nums[i] = 0; 
    }
  }
}

好厲害，佩服佩服