EASY NC#140 Math & Geometry
66. Plus One
📖 Problem
You are given a large integer represented as an integer array digits, where each digits[i] is the ith digit of the integer. The digits are ordered from most significant to least significant in left-to-right order. The large integer does not contain any leading 0's, except for the number 0 itself. Increment the large integer by one and return the resulting array of digits.
🧠 Visual Learning Aid
1 Model the input into the right structure
2 Choose the core technique and invariant
3 Execute step-by-step with a sample
4 Validate complexity and edge cases
JS/TS Refreshers
- •Array methods (`push`, `pop`, `shift`, `slice`)
- •Object/Map/Set usage patterns
- •Function parameter and return typing
Logical Thinking Concepts
- •Define invariants before coding
- •Check edge cases first (`[]`, single element, duplicates)
- •Estimate time/space before implementation
💡 Approach
- → Process digits from right to left
- → Add 1 and propagate carry if digit is 9
- → If all digits are 9, need to add a leading 1
- → Time: O(n), Space: O(1) or O(n) if new array needed
🛠️ Hints & Pitfalls
Hints
- •Process digits from right to left
- •Add 1 and propagate carry if digit is 9
- •If all digits are 9, need to add a leading 1
Common Pitfalls
- •Time: O(n), Space: O(1) or O(n) if new array needed
🧪 Test Cases
Hidden tests on submit: 2
Test Case 1
Not run Input:
plusOne([1,2,3]); Expected:
[1, 2, 4] Test Case 2
Not run Input:
plusOne([4,3,2,1]); Expected:
[4, 3, 2, 2] Test Case 3
Not run Input:
plusOne([9]); Expected:
[1, 0] 📝 Code Editor
📤 Output