Problem Statement:
Question: Given a pattern containing only Ns and Ms. N represents ascending and M represents descending, Each character (M or N) needs to display a sequence of numbers (2 numbers) explaining the ascending and descending order (for ex: 21 ->represents the ascending ->M). The second character in the patterns takes the last digit from the first character builds the sequence and so on. Please look at the example section below.
There could be multiple numbers satisfying the patterns. The goal is to find out the lowest numeric
the value following pattern.
Here are some constraints to this problem:
Example 1:
Input: M
Output: 21
Explanation: 2->1 shows descending and possible smallest numeric value. Even 65 or 75 can qualify, but
21 being the smallest numeric value is the correct answer.
Example 2:
Input: MNM
Output: 2143
Explanation: M represents descending 2->1. N represents ascending 1->4 (1 is coming from the last
character). M represent descending 4->3 (4 is coming from the last character sequence) — There would be
many numbers qualifying the pattern like 3142, 8796, 6241, etc. 2143 is the lowest numeric value for this
pattern sequence.
Number patterns and finding the possible smallest numeric value- This competitive coding challenge question was asked in one of the Goldman Sachs coding rounds.
This is really a tricky problem. I would recommend you to solve this problem by yourself first. Solve this competitive coding challenge question in any programming language you are familiar with, like C/C++, Java or Python.
Here is my Python solution to this problem.
#!/bin/python3
def findPossibleSmallestNumberMatchingPattern(pattern):
maxTemp=0
valLast=0
lenMsg=len(pattern)
if lenMsg>8:
return -1
out=[]
i=0
while i<lenMsg:
numofM=0
if pattern[i]=='N':
numofM=pattern[i+1: ].count('M')
if i==0:
maxTemp=numofM+2
valLast=valLast+1
out.append(str(valLast))
out.append(str(maxTemp))
valLast=maxTemp
else:
maxTemp=maxTemp+numofM+1
valLast=maxTemp
out.append(str(valLast))
for k in range(numofM):
valLast=valLast-1
out.append(str(valLast))
i=i+1
else:
if i==0:
j=i+1
numofM=0
#find the number of next M.
while j<lenMsg and pattern[j]=='M':
numofM += 1
j += 1
maxTemp=numofM+2
out.append(str(maxTemp))
out.append(str(maxTemp-1))
valLast=maxTemp-1
else:
out.append(str(valLast-1))
valLast=valLast-1
i=i+1
return "".join(out)
if __name__ == "__main__":
print(findPossibleSmallestNumberMatchingPattern("MNM"))
Output:
2143
We used various Python list methods like append() and properties like indexing/slicing in this programming solution.
If you are preparing for a job in any product-based company, keep solving coding challenge questions. It will even help you to improve your programming skills.
I am complete Python Nut, love Linux and vim as an editor. I hold a Master of Computer Science from NIT Trichy. I dabble in C/C++, Java too. I keep sharing my coding knowledge and my own experience on <b>CSEstack.org</b> portal.
1 is repeating. It should be 789654321.
I have a written a code that is partially correct bcoz it’s unable to solve the minimization problem but solving all other conditions.
For MNM output should be 2143 but I am getting 3241.
Please let me know if you are able to rewrite your code correctly.