leetcode-lintcode/4_median_of_two_sorted_arrays.java at master · lt616/leetcode-lintcode · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
/*
There are two sorted arrays nums1 and nums2 of size m and n respectively.

Find the median of the two sorted arrays. The overall run time complexity should be O(log (m+n)).

You may assume nums1 and nums2 cannot be both empty.

Example 1:

nums1 = [1, 3]
nums2 = [2]

The median is 2.0

Example 2:

nums1 = [1, 2]
nums2 = [3, 4]

The median is (2 + 3)/2 = 2.5
*/

class Solution {
    public double findMedianSortedArrays(int[] nums1, int[] nums2) {
        int size = nums1.length + nums2.length;
        int first, second;
        if (size % 2 == 0) {
            first = size / 2 - 1;
            second = size / 2;
        } else {
            first = size / 2;
            second = -1;
        }

        int sum = 0, i = 0, j = 0, index = -1;
        while (i < nums1.length || j < nums2.length) {
            int num;
            if (i < nums1.length && j < nums2.length) {
                if (nums1[i] < nums2[j]) {
                    num = nums1[i];
                    i ++;
                } else {
                    num = nums2[j];
                    j ++;
                }
            } else {
                if (i < nums1.length) {
                    num = nums1[i];
                    i ++;
                } else {
                    num = nums2[j];
                    j ++;
                }
            }

            if (++ index == first || index == second) {
                sum += num;
            }
        }

        return (second == -1) ? (double) sum : (double) sum / 2;
    }
}