4. Median of Two Sorted Arrays

class Solution:
    def findMedianSortedArrays(self, A: List[int], B: List[int]) -> float:
        if len(A)>len(B):
            A,B=B,A
        m,n=len(A),len(B)
        tot=(m+n)
        half = (m+n)>>1

        l,r=0,len(A)-1
        while True:
            c1=(l+r)>>1#c1--cut1 c2--cut2
            c2=half-(c1+1)-1# making c1 to 1 indexed and than make c2 to 0 indexed
            aleft=A[c1] if c1>=0 else float('-inf')#out of bounds
            aright=A[c1+1] if c1+1<m else float('inf')
            bleft=B[c2] if c2>=0 else float('-inf')
            bright=B[c2+1] if c2+1<n else float('inf')
            if aleft<=bright and bleft<=aright:
                if (tot)%2==1:
                    return min(aright,bright)#verify with example [3] [2,4] remember not max(aleft,bleft) when total is odd
                else:
                    return (max(aleft,bleft)+min(aright,bright))/2
            elif aleft>bright:
                r=c1-1
            else:
                l=c1+1