Cs50 Tideman Solution Review

"You’re not just looking for a loop," Kai said. "You’re looking for a chain . Before you lock a new edge from winner to loser , ask yourself: is there any path from the loser back to the winner using the edges already locked? If yes, this new edge would complete the cycle. Skip it."

The story is useful because the narrative (the cycle, the DFS, the "path back") sticks in your brain longer than any pseudocode. Next time you face Tideman, remember Maya and the Orchard.

She stared at her lock_pairs function. It was midnight. Her screen showed the dreaded red “:(” from check50 . Cs50 Tideman Solution

Maya ran check50 . Green smiles across the board. She leaned back.

"Yes," Maya sighed. "I sort the pairs. Strongest first. Alice over Bob? Lock it. Bob over Charlie? Lock it. Charlie over Alice? Don't lock it because it creates a cycle. But my cycle detection is wrong." "You’re not just looking for a loop," Kai said

Maya was the new programmer tasked with tabulating the votes. She had the first part down: counting each ballot to build a 2D array of preferences . It told her that Alice beat Bob (5 votes to 2), Bob beat Charlie (4 to 3), and Charlie beat Alice (3 to 2). A perfect, frustrating cycle.

Maya’s heart sank. She had been checking loser → X → winner . But what about loser → X → Y → winner ? If yes, this new edge would complete the cycle

Her job was to "lock in" the strongest edges of victory to create a directed graph of the winner—without creating a cycle.