Ȥ
Basic

FOR a=1 TO 13
FOR b=1 TO 13
IF b=a THEN GOTO 10
IF MOD(a*b+1,3)=0 THEN LET s=s+1
10 NEXT b
NEXT a
PRINT s
END

f9ơ40()
˭ԡ 714ڡ 0:06:05 MAIL:fttnm528@ybb.ne.jp 51673
٥륯åĥ
;1;2ǤФ褤Τ
54240
̤Ȥʤޤ

ǽȤ߹碌Ȼפä20Ƥޤ̾ܤʤΤǸľƵŤޤ
714ڡ 0:06:09 51674
ǯ
ϡ3dzä;꤬12ȹ礻Τ
;11,4,7,10,13
;22,5,8,11
ɤ餬ǤɤΤǡ2*5*4=40
714ڡ 0:08:21 51675
鯤ο
(,ˢ1,2or(2,1)mod3
1ȹƱʿ1,4,7,10,13̤
2ȹƱʿ2,5,8,11̤
顢ϡ5*4+4*540̤
//
714ڡ 0:08:29 51676
Mr.ǥ
٥륯åĥΡ#51674Ʊͤ˹ͤޤ
ڻԡ 714ڡ 0:08:34 51677
ߤ
֥򣳤dzä;ܤפʤƵˡ⤫ФʤäΤǡ
ɽߤʤΤäƵ§õäƤߤޤ

ȤꤢưƤߤƵ§õ롢äƤǤ֤Υѥ
Ūñ˵§ʬΤǡعǽФˤϥܥ⡣
714ڡ 0:15:57 51678
鯤ο
#51678

IJ0,1,2mod3"ɽɤäƤ򤤤ɤ⡢
ߥ+10 mod 3
(,)(1,2)or(2,1)mod 3
ˤĤƤС"ɽɤޤǤʤäΤǡ֤


ߥ+10 mod 5
ǤäʤС"ɽɤʤȡȤФ⡣
714ڡ 0:38:33 51679
Ȥ(8)
θ䡡ᡡߣorߣmod3
1(mod3)ϣࡡ2(mod3)ϣ
ȤƤߣߣᣴ̤
̸޻ԡ 714ڡ 1:27:39 51680
⡼ޥ
mod 3 0
1〜12ޤ...(12/3)(12/3)*2=32
13
1*4*2=8
ǡ40

14*11*2-4*3+4*1*2=84
-12*4*3+4*1*2=32
=40+84+32=156=13*12

so..
+13dzä1;ä䤳ä...^^;
714ڡ 1:37:53 51681
ֿء׾ι
3ˤ;ǿޤ!
714ڡ 3:55:47 51682
ֿء׾ι
ȤꤢĤΤ褦ˡңǤ

p (1..13).to_a.permutation(2).count{|i|(i[0]*i[1]+1)%3==0}
714ڡ 9:04:13 51683
ֿء׾ι
#51683 permutationĹΤǡn^2!=2(mod 3)Ǥ뤳Ȥդޤơ
p (1..13).map{|i|(1..13).count{|j|(i*j+1)%3==0}}.sum
Ȥޤ
714ڡ 9:23:21 51684
Ǹμ̿
ѥץDz򤤤ơ򤤤Ƥߤޤץϡ
import itertools
n=0
a=list(itertools.permutations([1,2,3,4,5,6,7,8,9,10,11,12,13],2))
for i in range(len(a)):
if (a[i][0]*a[i][1]+1)%==0:
n=n+1
print(n)
714ڡ 9:53:34 51685

pythonԥץ
print([(i*j+1) % 3==0 for i in range(1,14) for j in range(1,14)].count(True))
714ڡ 13:10:22 51686
Ф
פ֤Ǥ
1---2---3
4---5---6
7---8---9
10-11--12
13
¤٤ưֺ󤫤飱ġ󤫤飱
֤ϵդˤɤ
ߣߣᣴǤ
714ڡ 19:57:30 51687
鯤ο
#51679

>꤬
>ߥ+10 mod 5
>ǤäʤС"ɽɤʤȡȤФ⡣

ߥ+10 mod 5

(,)(1,4)or(2,2)or(3,3)or(4,1)mod5

dzä;꤬
05,102̤
11,6,113̤
22,7,123̤
33,8,133̤
44,9 2̤

(,)mod5ǡܤλϡƱȤʤȤդȡ

οϡ
3*2+3*2+3*2+2*324̤ꡣ

ꡢ(,)mod5ǡܤλդΤȡ
(,)(3,3)mod5λȤ䤹Τǡ
ɡ䤬ä
715ʶ 20:37:55 51690
ֿء׾ι
#51686 pythonǤone lineǤǤ͡
ǥ򤤤ûǤ

print([i*j%3for i in range(14) for j in range(14)].count(2))

;פʤȤǼ餷ޤ
716ڡ 5:55:31 51691
locker
ǽ 45=20 Ȥƴְ㤤ޤ֤θ 40 Ǥ͡
718ʷ 12:53:38 51692
礦路
#51692
⤽Ǵְ㤤ޤ
719ʲС 18:27:30 51693