Bird
Raised Fist0

In the following bottom-up DP code for integer break, which line causes incorrect results when n = 2?

medium🐞 Bug Identification Q7 of Q15
Dynamic Programming: Knapsack - Integer Break
In the following bottom-up DP code for integer break, which line causes incorrect results when n = 2?
def integer_break(n):
    dp = [0] * (n + 1)
    dp[1] = 1
    for i in range(2, n + 1):
        for j in range(1, i):
            dp[i] = max(dp[i], max(j, dp[j]) * (i - j))
    return dp[n]
Afor j in range(1, i):
Bfor i in range(2, n + 1):
Cdp[1] = 1
Ddp[i] = max(dp[i], max(j, dp[j]) * (i - j))
Step-by-Step Solution
Solution:
  1. Step 1: Understand dp initialization

    Setting dp[1] = 1 is incorrect because integer break requires at least two parts.
  2. Step 2: Impact on n=2

    For n=2, dp[2] depends on dp[1], which should be 0 to avoid invalid splits.
  3. Final Answer:

    Option C -> Option C
  4. Quick Check:

    dp[1] must be 0 to ensure valid splits [OK]
Quick Trick: dp[1] should be zero for integer break base case [OK]
Common Mistakes:
MISTAKES
  • Initializing dp[1] to 1 instead of 0
  • Misunderstanding base cases in DP
  • Assuming dp[1] represents a valid split product
Trap Explanation:
PITFALL
  • dp[1] = 1 looks intuitive but breaks correctness for small n
Interviewer Note:
CONTEXT
  • Tests understanding of DP base cases and correctness
Master "Integer Break" in Dynamic Programming: Knapsack

3 interactive learning modes - each teaches the same concept differently

Want More Practice?

15+ quiz questions · All difficulty levels · Free

Free Signup - Practice All Questions
More Dynamic Programming: Knapsack Quizzes