Merge Sorted Array

//两个指针从后往前扫一遍就行
void merge(int A[], int m, int B[], int n) {
    int i = m-1,j = n - 1 ,k = m+n-1;
    while(i>=0&&j>=0){
        if(A[i]>B[j]) A[k--] = A[i--];
        else A[k--] = B[j--];
    }
    while(i>=0) A[k--] = A[i--];
    while(j>=0) A[k--] = B[j--];
}