No Plagiarism!CUqOaUqwijtP82wipGweposted on PENANA 「庭院深深深幾許,三深不能排一起」有兩種解法。8964 copyright protection633PENANAhEVoc7cusq 維尼
637Please respect copyright.PENANAKkcVXPFwDY
8964 copyright protection633PENANAyCJFNYJ75Q 維尼
一、算「全部排列方式」再扣掉「深深深一起」的組合數8964 copyright protection633PENANA3erMGumDDO 維尼
*全部:有七個字元,所以為7!,但因「深」可互相調換,需再除以3!8964 copyright protection633PENANASaGc8yAHN9 維尼
*深深深:將「深深深」視為一字元,所以為5!8964 copyright protection633PENANAyFTfUOoK1k 維尼
(7!/3!)-5!=7208964 copyright protection633PENANAHAd7bkRsWu 維尼
637Please respect copyright.PENANAPPPBm5oziQ
8964 copyright protection633PENANA5kRS1CdhWH 維尼
二、算「深」各自獨立再加上「兩個深黏一起」的組合數8964 copyright protection633PENANArXj9T6FSws 維尼
*「深」獨立:其餘四字排列為4!,有五個位置給「深」安插,所以為(5×4×3),但因「深」可互相調換,需再除以3!8964 copyright protection633PENANAO9FWa8gekJ 維尼
*兩深一起:其餘四字排列為4!,將「深深」視為一字元安插,一樣五個位置,所以為(5×4)8964 copyright protection633PENANAKfnbDag9dS 維尼
4!×(5×4×3/3!+5×4)=720637Please respect copyright.PENANAAWO9hqJtqY
8964 copyright protection633PENANAuA3KX1JPy4 維尼
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