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 tom + n) to hold additional elements from nums2. The number of elements initialized innums1 and nums2 are m and n respectively.

方法一：从前向后生成最终序列，O(n+m)空间复杂度，运行速度较快

        int nums[m+n];        int i=0,j=0,k=0;        while(i<m&&j<n){            if(nums1[i]<nums2[j])                nums[k++]=nums1[i++];            else                nums[k++]=nums2[j++];        }        while(i<m)            nums[k++]=nums1[i++];        while(j<n)            nums[k++]=nums2[j++];        for(int i=0;i<m+n;i++)            nums1[i]=nums[i];

方法二：从后向前排序。O(1)空间复杂度，运行速度较慢

        int i=m-1,j=n-1,k=m+n-1;        while(i>=0&&j>=0){            if(nums1[i]>nums2[j])                nums1[k--]=nums1[i--];            else nums1[k--]=nums2[j--];        }        while(i>=0)            nums1[k--]=nums1[i--];        while(j>=0)            nums1[k--]=nums2[j--];