2020

• 2020-02-10BZOJ - 1257 余数之和(数学)
• 2020-02-03Educational Codeforces Round 81 (Rated for Div. 2) - D. Same GCDs(数学)
• 2020-01-15Educational Codeforces Round 79 (Rated for Div. 2) - D. Santa's Bot(数论)

2019

• 2019-07-23组合数学&概率&数学期望