4. Median of Two Sorted Arrays.md

class Solution {
public:
    double findMedianSortedArrays(vector<int>& nums1, vector<int>& nums2) {
        int n1=nums1.size(),n2=nums2.size();
        int mid=(n1+n2)>>1,i=0,j=0;
        mid+=(n1+n2)%2==1?1:0;
        int t=0,flag;
        while(t<mid){
            if(i<n1&&j<n2){
                if(nums1[i]<nums2[j]){i++;flag=0;}
                else {j++;flag=1;}
            }
            else {
                if(j<n2){j++;flag=1;}
                else {i++;flag=0;} 
            }
            t++;
        }
        int premid=  flag==1?nums2[j-1]:nums1[i-1];
        
        if((n1+n2)%2){
            return premid;
        }
        else{
            int behmid;
            if(i>=n1)  behmid=nums2[j];
            else if(j>=n2)   behmid=nums1[i];
            else behmid=nums1[i]<nums2[j]?nums1[i]:nums2[j];
            
            return float(behmid+premid)/2;

        }
        return nums1[i-1];
    }
        
};