MAY-25 2020 Challenge

Uncrossed Lines

We write the integers of A and B (in the order they are given) on two separate horizontal lines.
Now, we may draw connecting lines: a straight line connecting two numbers A[i] and B[j] such that:
A[i] == B[j];
The line we draw does not intersect any other connecting (non-horizontal) line.
Note that a connecting lines cannot intersect even at the endpoints: each number can only belong to one connecting line.
Return the maximum number of connecting lines we can draw in this way.

Example 1:

Input: A = [1,4,2], B = [1,2,4]
Output: 2
Explanation: We can draw 2 uncrossed lines as in the diagram.
We cannot draw 3 uncrossed lines, because the line from A[1]=4 to B[2]=4 will intersect the line from A[2]=2 to B[1]=2.

Example 2:

Input: A = [2,5,1,2,5], B = [10,5,2,1,5,2]
Output: 3

Example 3:

Input: A = [1,3,7,1,7,5], B = [1,9,2,5,1]
Output: 2

Note:

1 <= A.length <= 500

1 <= B.length <= 500

1 <= A[i], B[i] <= 2000

Solution in Python :

class Solution(object):

def maxUncrossedLines(self, A, B):

"""

:type A: List[int]

:type B: List[int]

:rtype: int

"""

memo={}

la,lb=len(A),len(B)

def helper(i,j):

if i>=la or j>=lb:

return 0

if (i,j) in memo:

return memo[i,j]

if A[i]==B[j]:

ans=1+helper(i+1,j+1)

else:

ans=max(helper(i+1,j),helper(i,j+1))

memo[i,j]=ans

return ans

return helper(0,0)

Comments

May-6 2020 Challenge

6. Majority Element Given an array of size n , find the majority element. The majority element is the element that appears more than ⌊ n/2 ⌋ times. You may assume that the array is non-empty and the majority element always exist in the array. Example 1: Input: [3,2,3] Output: 3 Example 2: Input: [2,2,1,1,1,2,2] Output: 2 Solution in Java class Solution { public int majorityElement(int[] num) { int m = num[0], cnt= 1; for (int i = 1; i < num.length; i++) { if (cnt == 0) { m= num[i]; cnt = 1; } else if (num[i] == m) { cnt++; } else cnt--; } return m;...

Leetcode 190. Reverse Bits. Python. Bit Manipulation

190 . Reverse Bits Reverse bits of a given 32 bits unsigned integer. Note: Note that in some languages, such as Java, there is no unsigned integer type. In this case, both input and output will be given as a signed integer type. They should not affect your implementation, as the integer's internal binary representation is the same, whether it is signed or unsigned. In Java, the compiler represents the signed integers using 2's complement notation . Therefore, in Example 2 above, the input represents the signed integer -3 and the output represents the signed integer -1073741825 . Example 1: Input: n = 00000010100101000001111010011100 Output: 964176192 (00111001011110000010100101000000) Explanation: The input binary string 00000010100101000001111010011100 represents the unsigned integer 43261596, so return 964176192 which its binary representation is 00111001011110000010100101000000 . Example 2: Input: n = 11111111111111111111...

Leetcode 58. Meeting Rooms II. Python (Easiest Explaination)

58. Meeting Rooms II Description Given an array of meeting time intervals consisting of start and end times [[s1,e1],[s2,e2],...] (si < ei) , find the minimum number of conference rooms required.) (0,8),(8,10) is not conflict at 8 Example Example1 Input : intervals = [(0,30),(5,10),(15,20)] Output : 2 Explanation : We need two meeting rooms room1 : ( 0 , 30 ) room2 : ( 5 , 10 ),( 15 , 20 ) Example2 Input: intervals = [( 2 , 7 )] Output: 1 Explanation: Only need one meeting room Solution : """ Definition of Interval: class Interval(object): def __init__(self, start, end): self.start = start self.end = end """ class Solution: """ @param intervals: an array of meeting time intervals @return: the minimum number of conference rooms required """ def min_meeting_rooms( self , intervals: List[Interval]) -> int : ...

LEETCODE SOLUTIONS

Search This Blog