Practice - Counting 1s and -1s in S'
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Practice Questions
Test your understanding with targeted questions
What does a valid sequence of 1s and -1s imply?
💡 Hint: Think about summation and how it behaves.
Calculate C(4, 2).
💡 Hint: This is a simple combinatorial count.
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Interactive Quizzes
Quick quizzes to reinforce your learning
What is the formula for the total number of sequences of n 1s and -1s?
💡 Hint: This is basic combinatorics — think pairs!
True or False: Bad sequences maintain non-negative sums.
💡 Hint: Reflect on our definition of bad sequences.
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Challenge Problems
Push your limits with advanced challenges
Consider the sequence S = {1, -1, 1, -1, -1, 1}. Show it's a bad sequence and demonstrate what its reflection would look like.
💡 Hint: Trace through the negative point.
Find the number of valid sequences for n=4 and explain why they are equivalent to C(8, 4) - C(8, 5).
💡 Hint: Break it down into visual paths.
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Reference links
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