median of two sorted arrays 

 1 double findKth(int a[], int m, int b[], int n, int k)
 2 {
 3     //always assume that m is equal or smaller than n
 4     if (m > n)
 5         return findKth(b, n, a, m, k);
 6     if (m == 0)
 7         return b[k - 1];
 8     if (k == 1)
 9         return min(a[0], b[0]);
10     //divide k into two parts
11     int pa = min(k / 2, m), pb = k - pa;
12     if (a[pa - 1] < b[pb - 1])
13         return findKth(a + pa, m - pa, b, n, k - pa);
14     else if (a[pa - 1] > b[pb - 1])
15         return findKth(a, m, b + pb, n - pb, k - pb);
16     else
17         return a[pa - 1];
18 }
19 
20 class Solution
21 {
22 public:
23     double findMedianSortedArrays(int A[], int m, int B[], int n)
24     {
25         int total = m + n;
26         if (total & 0x1)
27             return findKth(A, m, B, n, total / 2 + 1);
28         else
29             return (findKth(A, m, B, n, total / 2)
30                     + findKth(A, m, B, n, total / 2 + 1)) / 2;
31     }
32 };

 

posted on 2013-09-06 19:54  jumping_grass  阅读(158)  评论(0)    收藏  举报

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