返回题库

HMMT 十一月 2016 · 冲刺赛 · 第 36 题

HMMT November 2016 — Guts Round — Problem 36

专题
Contest Math / 竞赛数学
难度
L3
来源
HMMT

题目详情

英文原题

  1. [ 20 ] Find the number of positive integers less than 1000000 which are less than or equal to the sum of their proper divisors. If your answer is X and the actual value is Y , your score will bemax(0 , 20 − 80 | 1 − | ) rounded to the nearest integer.X Y
解析

英文解析

  1. [ 20 ] Find the number of positive integers less than 1000000 which are less than or equal to the sum of their proper divisors. If your answer is X and the actual value is Y , your score will bemax(0 , 20 − 80 | 1 − | ) rounded to the nearest integer.X
    Proposed by: Allen Liu y
    Answer: 247548
    N = 1000000
    s = [0] * Nans = 0
    for i in range(1, N):
    if i <= s[i]:
    ans += 1
    for j in range(i + i, N, i):
    s[j] += iprint(ans)