m n ( ) nums1 nums2。
, O(log(m + n))。
nums1 nums2 。
1:
nums1 = [1, 3]
nums2 = [2]
2.0
2:
nums1 = [1, 2]
nums2 = [3, 4]
(2 + 3)/2 = 2.5
class Solution {
public:
double findMedianSortedArrays(vector& nums1, vector& nums2) {
if(nums1.size() > nums2.size()){
return findMedianSortedArrays(nums2,nums1);
}
int m = nums1.size();
int n = nums2.size();
int left = 0,right=m,ansi = -1;
int median1 =0,median2 = 0;
while(left<=right){
int i=(left + right)/2;
int j=(m+n+1)/2 - i;
int nums_im1 = (i==0?INT_MIN:nums1[i-1]);
int nums_i = (i==m?INT_MAX:nums1[i]);
int nums_jm1 = (j==0?INT_MIN:nums2[j-1]);
int nums_j = (j==n?INT_MAX:nums2[j]);
if(nums_im1<=nums_j){
ansi = i;
median1 = max(nums_im1,nums_jm1);
median2 = min(nums_i,nums_j);
left = i+1;
}
else{
right = i-1;
}
}
return (m+n)%2 == 0?(median1+median2)/2.0:median1;
}
};