LeeCode 88. Merge Sorted Array 두 가지 해법

// Author : yqtao
// Date : 2016-7-6
// Email : [email protected]
/********************************************************************************** * * Given two sorted integer arrays A and B, merge B into A as one sorted array. * * Note: * You may assume that A has enough space (size that is greater or equal to m + n) * to hold additional elements from B. The number of elements initialized in A and B * are m and n respectively. * **********************************************************************************/
#include<iostream>
#include<vector>
using namespace std;
//Solutins 1: 4ms
void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
    int i = 0, j = 0, k = 0;
    vector<int>temp(nums1.begin(), nums1.end());  //using a vector to restore nums1,
    while (i<m&&j<n)
    {
        if (temp[i] <= nums2[j])
            nums1[k++] = temp[i++];
        else
            nums1[k++] = nums2[j++];
    }
    while (i<m)
        nums1[k++] = temp[i++];
    while (j<n)
        nums1[k++] = nums2[j++];
}
//Solution 2: 4ms,but i think this way is better then above
void merge(vector<int>& nums1, int m, vector<int>& nums2, int n) {
    int i = m - 1, j = n - 1, tar = m + n - 1;    //from end to head
    while (j >= 0) {
        nums1[tar--] = i >= 0 && nums1[i] > nums2[j] ? nums1[i--] : nums2[j--];
    }
}