推 c5onb:應該要考慮到n+1個數字才對 06/22 15:15
※ 引述《hirabbitt (兔子)》之銘言：
: Show that for every integer n there is a multiple of n
: that has only 0s and 1s in its decimal expansion.
: 以上...
: 謝謝了
考慮 1, 11, 111, 1111, ..., 11...1(n個)
共n個數,每個數均除以 n 觀察其餘數,必有兩數(設為a, b, a<b)之餘數相同
=> b-a 必為 n 之倍數, 而 b-a 寫出來是 1,0 之組合!
--
※ 發信站: 批踢踢實業坊(ptt.cc)
◆ From: 140.124.25.76