[LeetCode] Merge Sorted Array

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 to hold additional elements from B. The number of elements initialized in A and B are m and n respectively.

 解题思路：

额外开了空间，不开也可以，但是会比较麻烦。

class Solution {

public:

    void merge(int A[], int m, int B[], int n) {

        // IMPORTANT: Please reset any member data you declared, as

        // the same Solution instance will be reused for each test case.

        int *C = new int[m + n + 1];

        int a = 0, b = 0;

        for(int i = 0;i < m + n;i++)

        {

            if(a < m)

            {

                if(b < n)

                {

                    if(A[a] < B[b])

                        C[i] = A[a++];

                    else

                        C[i] = B[b++];

                }

                else

                    C[i] = A[a++];

            }

            else

            {

                if(b < n)

                    C[i] = B[b++];

                else

                    break;

            }

        }

        for(int i = 0;i < m + n;i++)

            A[i] = C[i];

    }

};