Many people are discussing recently HRT OA, I just finished taking a student here. The overall experience is actually more friendly than many people imagine: four questions are completed within a time limit, and the rhythm is relatively tight. However, as long as you have a solid foundation in algorithms and are familiar with common question types, you can basically complete it successfully within the time. This OA has a total of four questions, and students have to do it all once in 70 minutes. There is no repeated debugging or stuck thinking.
1.Dice scoring
Question description
Roll 3 6-sided dice and use whole numbers as the result A,B,C Representation, and then calculate the total score according to the following rules:
- The three dice numbers are exactly the same(
A = b = c): score =1000*a - Exactly two dice have the same number: score =
500*x(XAre the values of those two identical points) - The three dice have different numbers: score =
100*min(a, b, c)
Problem-solving ideas
First determine whether the three dice points are all the same, and if so, return 1000 times the number; if not, check whether two points have the same number, and if so, return 500 times the repeated points. If the first two are not satisfied, the minimum value of 100 times three points is returned.
2.Consonant substitution code
Question description
You want to implement a simple replacement password, only for memo (Memo) takes effect:
- Only affects consonants:
B,c,d,f,g,h,j,k,l,m,n,p,q,r,s,t,v,w,x,y,z(Both upper and lower case are counted), vowels and other characters remain unchanged. - Rule: Move the kth occurring consonant backward to the next consonant; if
ZJust loop toB. - Case must be preserved (uppercase remains uppercase, lowercase remains lowercase).
- The time complexity does not exceed
O(len(memo)²)That’s it.
Example:
Memo = "CodeSignal", K=3 → output "CodeTignam"
Explain:
- Original consonant:
C, d, S, g, n, l - 3rd consonant
SMove one position backward to becomeT, the rest remains unchanged.
Problem-solving ideas
First determine the consonant range (exclude the upper and lower case of vowels a/e/i/o/u), and then initialize the consonant counter. 2. Traverse the string, count the consonants when they encounter them, replace them with the next consonant (z->b, Z->B) when the count reaches k, and clear the count; non-consonants are directly retained, and finally the splicing result is obtained.
3. Maze and portal
Question description
You explore a rectangular matrix-shaped maze containing obstacles and portals. You start from the upper left corner (0, 0) Set off, the goal is to reach the lower right corner (n-1, m-1), and can only move all the way to the right.
Problem-solving ideas
Use a dictionary to record the transfer point, and a collection to record the location traveled. Start walking step by step from the starting point. If you step on an obstacle, you will directly return -1; if you reach the position you have visited before, it means you have entered a loop and return -2; if you successfully reach the end point, the number of steps will be output. Just pay attention to handling the transmission mechanism and status recording.
4. Maximum square area that can be embedded
The general idea of the topic
Given an array CityLine, each element represents the height of a skyscraper, the width of each building is fixed to 1, and they are closely adjacent to each other. Your task is to find the area of the largest square that can fit within this row of buildings.
Problem-solving ideas
Use binary search to guess the maximum square side length (ranging from 0 to the number of tall buildings), take the middle value mid each time, and verify whether there are consecutive mid building heights >= mid. If the verification passes, try a larger side length; if it fails, try a smaller side length, and finally the square of the maximum feasible side length is the answer.
What to do with the OA card time?
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