leetcode-java-88. Merge Sorted Array

/*Given two sorted integer arrays nums1 and nums2, merge nums2 intonums1 as one sorted array.Note: You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2. The number of elements initialized in nums1 and nums2 are m and n respectively. *//*思路：此题需要归并， 但是要节省额外的空间，将nums2合并到nums1，为了防止重复移动，则应该从后向前移动。：从后往前遍历A和B数组，每次把大的数字从A中m+n位置逐步往前放 */ public class Solution {     public void merge(int[] nums1, int m, int[] nums2, int n) {         int len1 = m - 1,             len2 = n - 1,             lenTotal = m + n -1;         while(len1 >= 0 && len2 >= 0) {             if(nums1[len1] >= nums2[len2]) {                 nums1[lenTotal--] = nums1[len1--];             } else {                 nums1[lenTotal--] = nums2[len2--];             }         }        //  就是nums2还有剩余的元素         if(len1 == -1) {             while(len2 >= 0) {                 nums1[lenTotal--] = nums2[len2--];             }         }     } }