Algorithm Notes
Summary: Non Decreasing Array — notes not yet curated.
Time: Estimate via loops/recurrences; common classes: O(1), O(log n), O(n), O(n log n), O(n^2)
Space: Count auxiliary structures and recursion depth.
Tip: See the Big-O Guide for how to derive bounds and compare trade-offs.
Big-O Guide
Source
"""
Non-decreasing Array
TODO: Add problem description
"""
from src.interview_workbook.leetcode._registry import register_problem
from src.interview_workbook.leetcode._types import Category, Difficulty
class Solution:
def solve(self, nums):
"""Check if the array can be made non-decreasing by modifying at most one element."""
modified = False
for i in range(1, len(nums)):
if nums[i] < nums[i - 1]:
if modified:
return False
modified = True
if i < 2 or nums[i] >= nums[i - 2]:
nums[i - 1] = nums[i]
else:
nums[i] = nums[i - 1]
return True
def demo() -> str:
"""Run a demo for the Non-decreasing Array problem."""
nums = [4, 2, 3]
print(f"Input nums: {nums}")
s = Solution()
result = s.solve(nums)
print(f"Final result: {result}")
return f"Non-decreasing Array result for {nums} -> {result}"
if __name__ == "__main__":
demo()
register_problem(
id=665,
slug="non_decreasing_array",
title="Non-decreasing Array",
category=Category.GREEDY,
difficulty=Difficulty.MEDIUM,
tags=["array", "greedy"],
url="https://leetcode.com/problems/non-decreasing-array/",
notes="",
)