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A game coloring [0,1] segment

Source: Belarus TST 2024

July 17, 2024
gamescombinatorics

Problem Statement

Olya and Tolya are playing a game on [0,1][0,1] segment. In the beginning it is white. In the first round Tolya chooses a number 0l10 \leq l \leq 1, and then Olya chooses a subsegment of [0,1][0,1] of length ll and recolors every its point to the opposite color(white to black, black to white). In the next round players change roles, etc. The game lasts 20242024 rounds. Let LL be the sum of length of white segments after the end of the game. If L>12L > \frac{1}{2} Olya wins, otherwise Tolya wins. Which player has a strategy to guarantee his win? A. Naradzetski