Znn3bq.jpeg
²é¿´: 465  |  »Ø¸´: 4
µ±Ç°Ö÷ÌâÒѾ­´æµµ¡£

ji_sir

Ìú¸Ëľ³æ (СÓÐÃûÆø)

[½»Á÷] Çó½ÌÒ»¸öÊýѧÎÊÌâ

For n>=2,we note Pn the number of permutations ¦Ò  of  the  set {1,2,¡­,n} such that there is a single integer i¡Ê{1,2,¡­,n-1}such that  ¦Ò(i)>¦Ò(i+1).Find Pn.
»Ø¸´´ËÂ¥
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû

ji_sir

Ìú¸Ëľ³æ (СÓÐÃûÆø)

²»Ê¤¸Ð¼¤£¡
2Â¥2006-11-03 22:53:59
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû

gorilla

Í­³æ (³õÈëÎÄ̳)

3Â¥2006-11-04 16:55:10
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû

ji_sir

Ìú¸Ëľ³æ (СÓÐÃûÆø)

¸ÐлgorillaµÄ´ð°¸¡£ÇëÎÊÄÜ·ñ¸æÖª¾ßÌåµÄ½âÌâ˼·£¿²»Ê¤¸Ðл
ÒýÓûØÌû:
Originally posted by gorilla at 2006-11-4 16:55:
(n-1)*n/2

4Â¥2006-11-05 13:32:57
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû

jakob

5Â¥2006-11-27 19:14:14
ÒÑÔÄ   »Ø¸´´ËÂ¥   ¹Ø×¢TA ¸øTA·¢ÏûÏ¢ ËÍTAºì»¨ TAµÄ»ØÌû
Ïà¹Ø°æ¿éÌø×ª ÎÒÒª¶©ÔÄÂ¥Ö÷ ji_sir µÄÖ÷Ìâ¸üÐÂ
×î¾ßÈËÆøÈÈÌûÍÆ¼ö [²é¿´È«²¿] ×÷Õß »Ø/¿´ ×îºó·¢±í
[¿¼ÑÐ] 0854µ÷¼Á +8 ³¤¹­°Á 2026-04-09 9/450 2026-04-09 14:37 by zhyzzh
[¿¼ÑÐ] 086000µ÷¼Á +4 Ê®Æßsa 2026-04-07 4/200 2026-04-09 09:27 by Ò¼ÍùŸoǰ
[¿¼ÑÐ] »¯Ñ§0703-Ò»Ö¾Ô¸211-338·ÖÇóµ÷¼Á +10 vants 2026-04-05 11/550 2026-04-08 16:02 by screening
[¿¼ÑÐ] Ò»Ö¾Ô¸211£¬»¯Ñ§Ñ§Ë¶£¬310·Ö£¬±¾¿ÆÖصãË«·Ç£¬Çóµ÷¼Á +10 ŬÁ¦·Ü¶·112 2026-04-07 10/500 2026-04-08 15:01 by screening
[¿¼ÑÐ] Çóµ÷¼Á +28 111623 2026-04-04 33/1650 2026-04-08 09:24 by ÔóÈó¶«·½
[¿¼ÑÐ] 313Çóµ÷¼Á +3 Ê®Áùʰ½ 2026-04-07 3/150 2026-04-07 23:20 by lbsjt
[¿¼ÑÐ] Çóµ÷¼Á +11 wwwwabcde 2026-04-07 11/550 2026-04-07 23:16 by JourneyLucky
[¿¼ÑÐ] ÉúÎ﹤³ÌÇóµ÷¼Á +13 ϲ»¶»¹ÊDz»¸ÊÐÄ 2026-04-05 13/650 2026-04-07 16:55 by Ecowxq666£¡
[¿¼ÑÐ] 372·Ö²ÄÁÏÓ뻯¹¤£¨085600£©Ó¢¶þÊý¶þÇóµ÷¼Á +4 À¶¼ãƬ 2026-04-06 4/200 2026-04-07 12:30 by dongzh2009
[¿¼ÑÐ] 277¹¤¿ÆÇóµ÷¼Á +10 1915668 2026-04-04 11/550 2026-04-06 23:53 by ÐÄæÂÒâ±±
[¿¼ÑÐ] ÉúÎïѧÇóµ÷¼Á Ò»Ö¾Ô¸»¦9£¬326·Ö +6 Áõīī 2026-04-06 6/300 2026-04-06 19:36 by lijunpoly
[¿¼ÑÐ] 0854Çóµ÷¼Á +4 assdll 2026-04-05 4/200 2026-04-06 12:29 by ÖзÉÔº¿Õ¹ÜѧԺÑ
[¿¼ÑÐ] 302·Ö 085601Çóµ÷¼ÁÍÆ¼ö +11 zyxÉϰ¶£¡ 2026-04-05 11/550 2026-04-05 22:13 by dongzh2009
[¿¼ÑÐ] Ò»Ö¾Ô¸ÉϺ£º£Ñó´óѧ083200ʳƷѧ˶£¬Çóµ÷¼Á£¬½ÓÊÜÆäËûרҵ083200 +4 whatÕÅ 2026-04-04 5/250 2026-04-05 14:07 by chw1980_0
[¿¼ÑÐ] ¿¼Ñе÷¼Á +4 zybz³å³å³å 2026-04-03 6/300 2026-04-04 13:08 by zybz³å³å³å
[¿¼ÑÐ] ÇóÉúÎïѧרҵµ÷¼Á-332·Ö +5 ÔÆ¶äåÞÍäÖ¸ÄÏ 2026-04-04 5/250 2026-04-04 10:05 by rzh123456
[¿¼ÑÐ] 322Çóµ÷¼Á +4 FZAC123 2026-04-03 4/200 2026-04-03 20:55 by zhq0425
[¿¼ÑÐ] Çóµ÷¼Á +8 akdhjs 2026-04-03 8/400 2026-04-03 18:17 by ´÷άING
[¿¼ÑÐ] 330Çóµ÷¼Á +3 °×ÉñÎØºôºô 2026-04-02 3/150 2026-04-03 10:15 by À¶ÔÆË¼Óê
[¿¼ÑÐ] 302Çóµ÷¼Á +9 zyxÉϰ¶£¡ 2026-04-02 9/450 2026-04-02 23:07 by Âí¶ù¿ì¿ìµØÅÜ
ÐÅÏ¢Ìáʾ
ÇëÌî´¦ÀíÒâ¼û