double findMedianSortedArrays(vector<int>& nums1, vector<int>& nums2) {
int m = nums1.size(), n = nums2.size();
if ((n + m)&1)
return findKthSortedArrays(nums1.begin(), m, nums2.begin(), n, (n + m) / 2 + 1);
else
return (findKthSortedArrays(nums1.begin(), m, nums2.begin(), n, (n + m) / 2 + 1) +
findKthSortedArrays(nums1.begin(), m, nums2.begin(), n, (n + m) / 2)) / 2.0;
}
double findKthSortedArrays(vector<int>::iterator nums1_begin, int m, vector<int>::iterator nums2_begin, int n, int k) {
if (m < n) {
swap(m, n);
swap(nums1_begin, nums2_begin);
}
if (n == 0)
return *(nums1_begin + k - 1);
if (k == 1)
return min(*nums1_begin, *nums2_begin);
int pb = min(k / 2, n), pa = k - pb;
if (*(nums1_begin + pa - 1) > *(nums2_begin + pb - 1))
return findKthSortedArrays(nums1_begin, m, nums2_begin + pb, n - pb, k - pb);
else if (*(nums1_begin + pa - 1) < *(nums2_begin + pb - 1))
return findKthSortedArrays(nums1_begin + pa, m - pa, nums2_begin, n, k - pa);
else
return *(nums1_begin + pa - 1);
}
double findKthSortedArrays(std::vector<int>::iterator it1, int m,
std::vector<int>::iterator it2, int n,
int k)
{
if (m > n)
return findKthSortedArrays(it2, n, it1, m, k);
if (m == 0)
return *(it2 + k - 1);
if (k == 1)
return std::min(*it1, *it2);
int pa = std::min(k / 2, m), pb = k - pa;
if (*(it1 + pa - 1) < *(it2 + pb - 1))
return findKthSortedArrays(it1 + pa, m - pa, it2, n, k - pa);
else if (*(it1 + pa - 1) > *(it2 + pb - 1))
return findKthSortedArrays(it1, m, it2 + pb, n - pb, k - pb);
else
return *(it1 + pa - 1);
}
