No Plagiarism!v9Whkta8USwHygqVUMAVposted on PENANA 「庭院深深深幾許,三深不能排一起」有兩種解法。8964 copyright protection178PENANAOmnSsUU7n7 維尼
182Please respect copyright.PENANA8ay6dtn4l0
8964 copyright protection178PENANA8Bdv9DtkI9 維尼
一、算「全部排列方式」再扣掉「深深深一起」的組合數8964 copyright protection178PENANAIFzuSPSn35 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 protection178PENANAvqZGEc7WDw 維尼
*深深深:將「深深深」視為一字元,所以為5!8964 copyright protection178PENANAVJrpRI1fwq 維尼
(7!/3!)-5!=7208964 copyright protection178PENANAMEHUyZWQE2 維尼
182Please respect copyright.PENANA1YvsIEyXnN
8964 copyright protection178PENANAr1RrjieJKU 維尼
二、算「深」各自獨立再加上「兩個深黏一起」的組合數8964 copyright protection178PENANAzUvuIUmsUo 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 protection178PENANAg02SpLAz0q 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 protection178PENANAz8HGUXuXd7 維尼
4!×(5×4×3/3!+5×4)=720182Please respect copyright.PENANAA8zmS5f9X5
8964 copyright protection178PENANAm9pBAkqThT 維尼
172.70.130.240
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