Median of Two Sorted Arrays(Java)

求2个数组的中位数

方法很多

但是时间复杂度各异

1利用数组copy方法先融合两个数组,然后排序，找出中位数

import java.lang.reflect.Array;
import java.util.Arrays;
import java.util.Collection;
import java.util.Collections;

public class _004MedianofTwoSortedArrays {

    public static void main(String[] args)
    {
        int a[]={2,3,5,9};
        int b[]={1,4,7,10,11};
        System.out.println(findMedianSortedArrays(a,b));
    }

     public static double findMedianSortedArrays(int A[], int B[])
     {
         int[] d3 = new int[A.length + B.length];
         System.arraycopy(A, 0, d3, 0, A.length);
         System.arraycopy(B, 0, d3, A.length, B.length);
         Arrays.sort(d3);
         System.out.println(Arrays.toString(d3));
         return d3.length%2!=0?d3[d3.length/2]/1.0:(d3[d3.length/2-1]+d3[d3.length/2])/2.0;

      }

}

2是循环判断插入新数组中 等于说不用内置copy方法自己写一个替代

 1 import java.util.Arrays;
 2
 3
 4 public class _004_2Median {
 5
 6     public static void main(String[] args) {
 7         // TODO Auto-generated method stub
 8         int a[]={2,34};
 9         int b[]={1,4,9};
10         System.out.println(findMedianSortedArrays(a,b));
11     }
12
13     private static double findMedianSortedArrays(int[] a, int[] b) {
14         int k=a.length+b.length;
15         System.out.println(k);
16         int[] c=new int[k];
17         int i=0,j=0,m=0;
18         while(m!=k)
19         {
20             if(i==a.length)
21             {
22                 c[m]=b[j];
23                 j++;
24
25             }
26             else if(j==b.length)
27             {
28                 c[m]=a[i];
29                 i++;
30             }
31             else if(a[i]<b[j])
32             {
33                 c[m]=a[i];
34                 i++;
35
36             }
37             else
38             {
39                 c[m]=b[j];
40                 j++;
41
42
43             }
44             m++;
45         }
46
47         return k%2==0?(c[k/2-1]+c[k/2])/2.0:c[k/2]/1.0;
48
49     }
50
51 }

3第三种递归方法有待研究