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HMMT 二月 2005 · TEAM1 赛 · 第 4 题

HMMT February 2005 — TEAM1 Round — Problem 4

专题
Discrete Math / 离散数学
难度
L3
来源
HMMT

题目详情

  1. [35] Show that all other rectangles of even area are (1 , 2)-tileable.
解析
  1. [35] Show that all other rectangles of even area are (1 , 2)-tileable. Solution: First, we demonstrate that there exist (1 , 2)-tilings of 2 × 4, 3 × 4, 3 × 6, and 5 × 6 rectangles. Now, notice that by combining these rectangles, we can form any rectangle of even area other than those described in the previous problem: using the first rectangle, we can form any 2 × n rectangle with 4 | n . By combining the first two, we can form any m × 4 rectangle with m ≥ 2, and by combining the last three, we can form any m × 6 rectangle with m ≥ 3. From these, we can form any m × n rectangle with m ≥ 3 and n even and greater than 2, completing the proof.