[LintCode/LeetCode] Merge Sorted Array

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--];
        }
    }

some weird solution...

class Solution {
    public void merge(int[] nums1, int m, int[] nums2, int n) {
        int i = m-1, j = n-1, k = m+n-1;
        while (k >= 0) {
            if (i >= 0 && j >= 0 && nums1[i] >= nums2[j]) {
                nums1[k] = nums1[i];
                i--;
            } else if (i >= 0 && j >= 0 && nums1[i] < nums2[j]) {
                nums1[k] = nums2[j];
                j--;
            } else if (i < 0 && j >= 0) {
                nums1[k] = nums2[j];
                j--;
            } else {
                return;
            }
            k--;
        }
        return;
    }
}