leetcode 4 golang Median of Two Sorted Arrays

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)).

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

两个有序数组的中卫数，可以转换为求第k小的数

奇数是找到第k小的就可以了

偶数是找到k 和 k + 1 在取平均值

func findMedianSortedArrays(nums1 []int, nums2 []int) float64 {

n1 := nums1
n2 := nums2

pa := 0 //第一个数组的指针
pb := 0 //第二个数组的指针

k := 0 //找到的第k小的数

n1len := len(n1)
n2len := len(n2)

first := 0 //存最后找到的数
second := 0 //存最后找到的数

max := (n1len + n2len) / 2 //k到这个值停止

for {

if k > max {
break
}

min := 0

//考虑不一样长的问题
if pa < n1len && pb < n2len{

item_n1 := n1[pa]
item_n2 := n2[pb]

if item_n1 < item_n2 {
min = item_n1
pa ++
k++
}else{
min = item_n2
pb++
k++
}
}else if pa < n1len {
min = n1[pa]
pa ++
k++
}else{
min = n2[pb]
pb++
k++
}
//考虑奇数偶数情况
if (n1len + n2len) % 2 == 0 {

if (k - 1) == (max - 1) {
first = min
}

if (k - 1) == max {
second = min
}

}else{
if (k - 1) == max {
first = min
second = 0
}
}
}

if (n1len + n2len) % 2 == 0{
return (float64(first) + float64(second)) / 2
}else{
return float64(first)
// fmt.Println(first)
}

}