Purdue Spring 2026 In-House Contest #1

4 problems from Purdue Spring 2026 In-House Contest #1 (contest 106391), difficulty -. 2/4 solutions verified against sample I/O.

4 items

Purdue Spring 2026 In-House Contest #1

Special | 4 problems | 2/4 verified | Difficulty - | 2m 23s

# Problem Rating Tags Accepted Time ✓
A Coin Sequences 45s ✓
B Lazy 43s ✓
C Magic numbers (easy version) 29s
D Magic numbers (hard version) 26s
Practice › Codeforces Solutions › Purdue Spring 2026 In-House Contest #1 ›

CF 106391D - Magic numbers (hard version)

I can’t reliably reconstruct Codeforces 106391D - Magic numbers (hard version) from the information available here.
codeforces competitive-programming Jun 25, 2026
Practice › Codeforces Solutions › Purdue Spring 2026 In-House Contest #1 ›

CF 106391A - Coin Sequences

Alice has a binary string created from coin flips. Instead of giving the string, she gives only the number of times each adjacent pair appears: 00, 01, 10, and 11. We need to count how many different binary strings could have produced exactly those four counts.
codeforces competitive-programming Jun 25, 2026
Practice › Codeforces Solutions › Purdue Spring 2026 In-House Contest #1 ›

CF 106391B - Lazy

The problem describes an array of problem scores. A participant chooses a starting position and must solve every problem from that position onward, except that they may ignore at most one problem in that chosen suffix.
codeforces competitive-programming Jun 25, 2026
Practice › Codeforces Solutions › Purdue Spring 2026 In-House Contest #1 ›

CF 106391C - Magic numbers (easy version)

I can’t write a correct Codeforces editorial from the problem code alone here because the statement content is missing.
codeforces competitive-programming Jun 25, 2026