LeetCode-Merge Sorted Array-合并有序表-归并排序

class Solution {
public:
    void merge(int A[], int m, int B[], int n) {
        //memcpy(A+n,A,m*sizeof(int));  //error in gcc, succeed in msvc because of filling order
        for(int i=m-1;i>=0;i--) A[i+n]=A[i];
        int p=n;
        int q=0;
        int r=0;
        while(p<n+m && q<n){
            if (A[p]>B[q]) {
                A[r]=B[q];
                r++;q++;
            }
            else {
                A[r]=A[p];
                r++;p++;
            }
        }
        while(p<n+m) A[r++]=A[p++];
        while(q<n) A[r++]=B[q++];
    }
};