Merge Sorted Array详解编程语言

Given two sorted integer arrays A and B, merge B into A as one sorted array. 
 
Example 
A = [1, 2, 3, empty, empty], B = [4, 5] 
 
After merge, A will be filled as [1, 2, 3, 4, 5] 
 
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 and n respectively.

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) { 
        int index = m + n - 1; 
        while (m > 0 && n > 0) { 
            if (A[m - 1] > B[n - 1]) { 
                A[index] = A[m - 1]; 
                --m; 
            } else { 
                A[index] = B[n - 1]; 
                --n; 
            } 
            --index; 
        } 
 
        // B has elements left 
        while (n > 0) { 
            A[index] = B[n - 1]; 
            --n; 
            --index; 
        } 
    } 
};

class Solution { 
    /** 
     * @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 
     */ 
    public void mergeSortedArray(int[] A, int m, int[] B, int n) { 
        if (A == null || B == null) return; 
 
        int index = m + n - 1; 
        while (m > 0 && n > 0) { 
            if (A[m - 1] > B[n - 1]) { 
                A[index] = A[m - 1]; 
                m--; 
            } else { 
                A[index] = B[n - 1]; 
                n--; 
            } 
            index--; 
        } 
 
        // B has elements left 
        while (n > 0) { 
            A[index] = B[n - 1]; 
            n--; 
            index--; 
        } 
    } 
}