[LintCode] 合并排序数组II

class Solution {
public:
    /**
     * @param A: sorted integer array A which has m elements, 
     *           but size of A is m+n
     * @param B: sorted integer array B which has n elements
     * @return: void
     */
    void mergeSortedArray(int A[], int m, int B[], int n) {
        // write your code here
        int pa = m - 1, pb = n - 1, p = m + n - 1;
        while (pa >= 0 && pb >= 0) {
            if (A[pa] >= B[pb]) A[p--] = A[pa--];
            else A[p--] = B[pb--];
        }
        while (pb >= 0) A[p--] = B[pb--];
    }
};