88.Merge-Sorted-Array

88. Merge Sorted Array

题目地址

题目描述

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

代码

Approach #1 Two Pointers

public class Solution {
public void mergeSortedArray (int[] A, int m, int[] B, int n) {
if (A == null || B == null) return;
int index = m + n - 1;
while (m > 0 && n > 0) {
if (A[m - 1] > B[n - 1]) {
A[index] = A[m - 1];
m--;
} else {
A[index] = A[n - 1];
n--;
}
index--;
}
while (n > 0) {
A[index] = B[n - 1];
n--;
index--;
}
}
}