Overview

It seems that coding tests are conducted overseas in interviews with engineers, and in many cases, the main thing is to implement specific functions and classes according to the theme.

Apparently, many engineers take measures on the site called LetCode.

It is a site that trains the algorithmic power that can withstand the coding test that is being done in the early story, and it is an inevitable path for those who want to build a career at an overseas tech company.

I wrote it in a big way, but I have no plans to have such an interview at the moment.

However, as an IT engineer, it would be better to have the same level of algorithm power as a person, so I would like to solve the problem irregularly and write down the method I thought at that time as a memo.

Leetcode

I'm solving it with Python3.

Leet Code Table of Contents Starting from Zero

Last time Leet Code Day70 starting from zero "295. Find Median from Data Stream"

Right now, I'm prioritizing the Medium of the Top 100 Liked Questions. I solved all Easy, so if you are interested, please go to the table of contents.

Twitter I'm doing it.

** Technical Blog Started! !! ** ** I think the technology will write about LetCode, Django, Nuxt, and so on. ** This is faster to update **, so please bookmark it!

problem

1496. Path Crossing

The difficulty level is Easy. This is the most recently added Easy issue.

The problem is that given a path of a string such as path [i] ='N','S','E','W', each represents one unit of movement. It starts from the origin (0, 0) on the two-dimensional plane and walks on the path specified by path. Returns True if the paths intersect at any point, that is, if you are in a location you have visited before. Otherwise, it returns False.

I can't put an example because of the image, so please check it by yourself.

solution

I took the method of managing the coordinates with x and y and managing the first coordinates with dict. Hmm. I don't think it's very smart, but it turns path with a for statement and changes the coordinates if it matches each string. However, even with this, the speed itself is high, probably because the number of answers is small ... I can't say anything, but for the time being, this is it.

class Solution:
    def isPathCrossing(self, path: str) -> bool:
        x = y = 0
        isVisited = {(0,0):True}
        for i in path:
            if i == 'N':
                y += 1
            elif i == 'E':
                x += 1
            elif i == 'S':
                y -= 1
            else:
                x -= 1
            if isVisited.get((x,y)):
                return True
            isVisited[(x,y)] = True
        return False
# Runtime: 24 ms, faster than 96.92% of Python3 online submissions for Path Crossing.
# Memory Usage: 14 MB, less than 100.00% of Python3 online submissions for Path Crossing.

Is it better to write in Java or a switch statement ...? This time I posted it to discuss as a new issue. Simple Python Solution

I'm nervous, but if you do this, you can get advice from smarter people!

So that's it for this time. Thank you for your hard work.

[PYTHON] Let Code Day71 Starting from Zero "1496. Path Crossing"

Overview

problem

solution