# 88 Merge Sorted Array (有圖)

標準公式題: 熟記 while，因為有時比 for 好用 / 多想一點 Edge Case

LeetCode

Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.

Note:

The number of elements initialized in nums1 and nums2 are m and n respectively.
You may assume that nums1 has enough space 
(size that is greater or equal to m + n) to hold additional elements from nums2.

input: 給兩個已經排序好的 Array 
output: 合併成一個排好的大 Array，而且不能用額外空間

Example:

Input:
nums1 = [1,2,3,0,0,0], m = 3
nums2 = [2,5,6],       n = 3

Output: [1,2,2,3,5,6]

/**
 * @param {number[]} nums1
 * @param {number} m
 * @param {number[]} nums2
 * @param {number} n
 * @return {void} Do not return anything, modify nums1 in-place instead.
 */
var merge = function(nums1, m, nums2, n) {}

var merge = function(nums1, m, nums2, n) {
    let i = 0
    let j = 0;
    let index = 0
    let nums1Copy = nums1.slice(0, m);
  
  
    while(i< m && j<n){
        if(nums1Copy[i] <= nums2[j]){
            nums1[index++] = nums1Copy[i++] 
        } else {
          nums1[index++] = nums2[j++]
        }
    }
    
   while(j<n){
     nums1[index++] = nums2[j++]
   }
  
   while(i<m){
     nums1[index++] = nums1Copy[i++] 
   }
};