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 andn respectively.
思路：从后往前复制，注意两个数组都为空或者其中一个数组为空的情况。
时间复杂度O(n),空间复杂度O(1)
1 class Solution { 2 public: 3 void merge(int A[], int m, int B[], int n) { 4 if (n == 0) 5 return; 6 int index = m + n - 1; 7 int ia = m - 1; 8 int ib = n - 1; 9 while (index >= 0) { 10 const int val_a = ia == -1 ? INT_MIN : A[ia]; 11 const int val_b = ib == -1 ? INT_MIN : B[ib]; 12 if (val_a > val_b) { 13 A[index--] = val_a; 14 --ia; 15 } else { 16 A[index--] = val_b; 17 --ib; 18 } 19 } 20 } 21 };
原文：http://www.cnblogs.com/vincently/p/4121008.html