Re: [其他] 請教一題證明題

[robertshih (施抄)]

※ 引述《heroherog (唯一)》之銘言：
: 題目是
:  1      3      5              2n-1      1
: ── * ── * ── * ...... * ──   < ─
:  2      4      6               2n      10
: 請問 n = ? 成立 ，並證明之。
: 除了硬算之外我真的想不到怎麼解...
: 拜託高手幫忙，感激不盡

#include<stdio.h>

int main(){
        double m=1.0;
        int i;
        for(i=1;m>=0.1;i+=2){
                m*=(double)i/(double)(i+1);
                printf("i = %d, m = %lf\n", i, m);
        }
        return 0;
}

i = 1, m = 0.500000
i = 3, m = 0.375000
i = 5, m = 0.312500
i = 7, m = 0.273438
i = 9, m = 0.246094
i = 11, m = 0.225586
i = 13, m = 0.209473
i = 15, m = 0.196381
i = 17, m = 0.185471
i = 19, m = 0.176197
i = 21, m = 0.168188
i = 23, m = 0.161180
i = 25, m = 0.154981
i = 27, m = 0.149446
i = 29, m = 0.144464
i = 31, m = 0.139950
i = 33, m = 0.135834
i = 35, m = 0.132061
i = 37, m = 0.128585
i = 39, m = 0.125371
i = 41, m = 0.122386
i = 43, m = 0.119604
i = 45, m = 0.117004
i = 47, m = 0.114567
i = 49, m = 0.112275
i = 51, m = 0.110116
i = 53, m = 0.108077
i = 55, m = 0.106147
i = 57, m = 0.104317
i = 59, m = 0.102578
i = 61, m = 0.100924
i = 63, m = 0.099347 <- 2n - 1 = 63, n = 32

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◆ From: 140.112.91.122
推 jimmy780331 :我很好奇 別人用你數學題目 你用程式碼給他看 有多少
→ jimmy780331 :人懂? 用別人學過的東西去講解 才能讓人吸收到吧?
→ jimmy780331 :況且 此題都說 "證明"
→ jimmy780331 :第一行打錯字  別人"問"你
→ jameschou   :同樓上 這程式碼雖然很簡單 但題目是要證明 不懂原po
推 icu         :其實我覺得蠻有趣的~~哈哈
→ jameschou   :這樣有什麼意義 而且也不是第一次這樣搞了 我覺得很
→ jameschou   :無聊
→ a88241050   :PO程式碼幹嘛,考證明題你寫程式碼教授會給你分嗎
→ gimO        :無意義
推 doa2        :也算是窮舉證明啦XD