Problem

Given two sorted integer arrays A and B, merge B into A as one sorted array.

Notice

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.

Example

A = [1, 2, 3, empty, empty], B = [4, 5]

After merge, A will be filled as [1, 2, 3, 4, 5]

Tags

Sorted Array Array Facebook

Solution

class Solution {
    public void mergeSortedArray(int[] A, int m, int[] B, int n) {
        int index = m+n-1, i = m-1, j = n-1;
        while (i >= 0 && j >= 0) {
            if (A[i] > B[j]) A[index--] = A[i--];
            else A[index--] = B[j--];
        }
        while (i >= 0) A[index--] = A[i--];
        while (j >= 0) A[index--] = B[j--];
    }
}