회문의 날을 구해보자 Palindrome Day
오늘은 20211202 로 회문의 날이다.
회문(回文)은 그대로 읽으나 뒤에서 읽으나 똑같은 문장을 회문이라 한다.
https://namu.wiki/w/%ED%9A%8C%EB%AC%B8
오늘 직전의 회문의 날은 20200202 였으며 이날은 909년만에 돌아온 회문의 날이라고 한다 ㅎㅎ
기자들이 기사를 어떻게 쓰는지..ㅎㅎ... 20200202 직전 회문의 날은 아래 코드로 돌려보니 20111102 이다 ㅎㅎ 9년만인셈
오늘 이후의 회문의 날은 3030년 03월 03일 이다.
무려 1009년 뒤의 일이다 ㅎㅎ
역시 아래코드의 결과로 보면 다음 회문의 날은 20300302 이다 ㅎ 역시 9년 뒤 ㅎ
평생 한번도 회문의 날을 겪지 못하고 가는 사람들도 많을 것인데 사는동안 이런 날을 2틀이나 경험하다니 ㅎㅎ 나는 대단한 행운아인가? ㅎㅎ 행운아가 아닌듯 싶다 왜냐하면 아래 결과를 보면 평균 27년마다 한번씩은 돌아온다 ㅎㅎ
나라에 따라 날짜를 yyyymmdd 로 쓰지 않는 나라도 있기 때문에 나라마다 회문의 날은 조금씩 달라질 수도 있다. 구글에서 palindrome day 로 검색을 해보면 나라별 날짜 표기법에 따른 결과도 많이 보인다.
palindrome day - Google 검색
Wake up, madam! Today's... www.thetimes.co.uk
www.google.co.kr
이런 특별한 날을 경험하기도 쉬운 일은 아닐진데 하루하루 감사하는 마음으로 살아가야 하겠다. ㅎㅎ
아래는 다음 회문의 날은 언제일까가 궁금하여 돌려본 코드이다
0001년부터 9999년까지 돌려서 확인해본 결과 총 366일이 회문의 날이 되겠다.(평균으로 구해보면 약 27년마다 하루인데 리스트를 보면 간격이 긴 경우를 제외하고 대략 9~10년마다 한번씩은 돌아오는 듯 싶다 ㅎㅎㅎ)
int main(int argc, char* argv[])
{
int md[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }, year, month, day, i, total=0;
char date[9] = { 0, }, temp[9] = { 0, };
for (year = 1; year <= 9999; year++) {
if (year % 400 == 0 || (year % 100 != 0 && year % 4 == 0))
md[1] = 29;
else
md[1] = 28;
for (month = 1; month <= 12; month++) {
for (day = 1; day <= md[month - 1]; day++) {
sprintf(date, "%04d%02d%02d", year, month, day);
for (i = 0; i < 8; i++)
temp[i] = date[7-i];
if (strcmp(date, temp) == 0) {
printf("%04d-%02d-%02d %s %s\n", year, month, day, date, temp);
total++;
}
}
}
}
printf("Total Palindrome days : %d", total);
return 0;
}
전체 회문의 날 리스트(위 코드 결과)
0101-10-10 01011010 01011010
0110-01-10 01100110 01100110
0111-11-10 01111110 01111110
0120-02-10 01200210 01200210
0121-12-10 01211210 01211210
0130-03-10 01300310 01300310
0140-04-10 01400410 01400410
0150-05-10 01500510 01500510
0160-06-10 01600610 01600610
0170-07-10 01700710 01700710
0180-08-10 01800810 01800810
0190-09-10 01900910 01900910
0201-10-20 02011020 02011020
0210-01-20 02100120 02100120
0211-11-20 02111120 02111120
0220-02-20 02200220 02200220
0221-12-20 02211220 02211220
0230-03-20 02300320 02300320
0240-04-20 02400420 02400420
0250-05-20 02500520 02500520
0260-06-20 02600620 02600620
0270-07-20 02700720 02700720
0280-08-20 02800820 02800820
0290-09-20 02900920 02900920
0301-10-30 03011030 03011030
0310-01-30 03100130 03100130
0311-11-30 03111130 03111130
0321-12-30 03211230 03211230
0330-03-30 03300330 03300330
0340-04-30 03400430 03400430
0350-05-30 03500530 03500530
0360-06-30 03600630 03600630
0370-07-30 03700730 03700730
0380-08-30 03800830 03800830
0390-09-30 03900930 03900930
1001-10-01 10011001 10011001
1010-01-01 10100101 10100101
1011-11-01 10111101 10111101
1020-02-01 10200201 10200201
1021-12-01 10211201 10211201
1030-03-01 10300301 10300301
1040-04-01 10400401 10400401
1050-05-01 10500501 10500501
1060-06-01 10600601 10600601
1070-07-01 10700701 10700701
1080-08-01 10800801 10800801
1090-09-01 10900901 10900901
1101-10-11 11011011 11011011
1110-01-11 11100111 11100111
1111-11-11 11111111 11111111
1120-02-11 11200211 11200211
1121-12-11 11211211 11211211
1130-03-11 11300311 11300311
1140-04-11 11400411 11400411
1150-05-11 11500511 11500511
1160-06-11 11600611 11600611
1170-07-11 11700711 11700711
1180-08-11 11800811 11800811
1190-09-11 11900911 11900911
1201-10-21 12011021 12011021
1210-01-21 12100121 12100121
1211-11-21 12111121 12111121
1220-02-21 12200221 12200221
1221-12-21 12211221 12211221
1230-03-21 12300321 12300321
1240-04-21 12400421 12400421
1250-05-21 12500521 12500521
1260-06-21 12600621 12600621
1270-07-21 12700721 12700721
1280-08-21 12800821 12800821
1290-09-21 12900921 12900921
1301-10-31 13011031 13011031
1310-01-31 13100131 13100131
1321-12-31 13211231 13211231
1330-03-31 13300331 13300331
1350-05-31 13500531 13500531
1370-07-31 13700731 13700731
1380-08-31 13800831 13800831
2001-10-02 20011002 20011002
2010-01-02 20100102 20100102
2011-11-02 20111102 20111102
2020-02-02 20200202 20200202
2021-12-02 20211202 20211202
2030-03-02 20300302 20300302
2040-04-02 20400402 20400402
2050-05-02 20500502 20500502
2060-06-02 20600602 20600602
2070-07-02 20700702 20700702
2080-08-02 20800802 20800802
2090-09-02 20900902 20900902
2101-10-12 21011012 21011012
2110-01-12 21100112 21100112
2111-11-12 21111112 21111112
2120-02-12 21200212 21200212
2121-12-12 21211212 21211212
2130-03-12 21300312 21300312
2140-04-12 21400412 21400412
2150-05-12 21500512 21500512
2160-06-12 21600612 21600612
2170-07-12 21700712 21700712
2180-08-12 21800812 21800812
2190-09-12 21900912 21900912
2201-10-22 22011022 22011022
2210-01-22 22100122 22100122
2211-11-22 22111122 22111122
2220-02-22 22200222 22200222
2221-12-22 22211222 22211222
2230-03-22 22300322 22300322
2240-04-22 22400422 22400422
2250-05-22 22500522 22500522
2260-06-22 22600622 22600622
2270-07-22 22700722 22700722
2280-08-22 22800822 22800822
2290-09-22 22900922 22900922
3001-10-03 30011003 30011003
3010-01-03 30100103 30100103
3011-11-03 30111103 30111103
3020-02-03 30200203 30200203
3021-12-03 30211203 30211203
3030-03-03 30300303 30300303
3040-04-03 30400403 30400403
3050-05-03 30500503 30500503
3060-06-03 30600603 30600603
3070-07-03 30700703 30700703
3080-08-03 30800803 30800803
3090-09-03 30900903 30900903
3101-10-13 31011013 31011013
3110-01-13 31100113 31100113
3111-11-13 31111113 31111113
3120-02-13 31200213 31200213
3121-12-13 31211213 31211213
3130-03-13 31300313 31300313
3140-04-13 31400413 31400413
3150-05-13 31500513 31500513
3160-06-13 31600613 31600613
3170-07-13 31700713 31700713
3180-08-13 31800813 31800813
3190-09-13 31900913 31900913
3201-10-23 32011023 32011023
3210-01-23 32100123 32100123
3211-11-23 32111123 32111123
3220-02-23 32200223 32200223
3221-12-23 32211223 32211223
3230-03-23 32300323 32300323
3240-04-23 32400423 32400423
3250-05-23 32500523 32500523
3260-06-23 32600623 32600623
3270-07-23 32700723 32700723
3280-08-23 32800823 32800823
3290-09-23 32900923 32900923
4001-10-04 40011004 40011004
4010-01-04 40100104 40100104
4011-11-04 40111104 40111104
4020-02-04 40200204 40200204
4021-12-04 40211204 40211204
4030-03-04 40300304 40300304
4040-04-04 40400404 40400404
4050-05-04 40500504 40500504
4060-06-04 40600604 40600604
4070-07-04 40700704 40700704
4080-08-04 40800804 40800804
4090-09-04 40900904 40900904
4101-10-14 41011014 41011014
4110-01-14 41100114 41100114
4111-11-14 41111114 41111114
4120-02-14 41200214 41200214
4121-12-14 41211214 41211214
4130-03-14 41300314 41300314
4140-04-14 41400414 41400414
4150-05-14 41500514 41500514
4160-06-14 41600614 41600614
4170-07-14 41700714 41700714
4180-08-14 41800814 41800814
4190-09-14 41900914 41900914
4201-10-24 42011024 42011024
4210-01-24 42100124 42100124
4211-11-24 42111124 42111124
4220-02-24 42200224 42200224
4221-12-24 42211224 42211224
4230-03-24 42300324 42300324
4240-04-24 42400424 42400424
4250-05-24 42500524 42500524
4260-06-24 42600624 42600624
4270-07-24 42700724 42700724
4280-08-24 42800824 42800824
4290-09-24 42900924 42900924
5001-10-05 50011005 50011005
5010-01-05 50100105 50100105
5011-11-05 50111105 50111105
5020-02-05 50200205 50200205
5021-12-05 50211205 50211205
5030-03-05 50300305 50300305
5040-04-05 50400405 50400405
5050-05-05 50500505 50500505
5060-06-05 50600605 50600605
5070-07-05 50700705 50700705
5080-08-05 50800805 50800805
5090-09-05 50900905 50900905
5101-10-15 51011015 51011015
5110-01-15 51100115 51100115
5111-11-15 51111115 51111115
5120-02-15 51200215 51200215
5121-12-15 51211215 51211215
5130-03-15 51300315 51300315
5140-04-15 51400415 51400415
5150-05-15 51500515 51500515
5160-06-15 51600615 51600615
5170-07-15 51700715 51700715
5180-08-15 51800815 51800815
5190-09-15 51900915 51900915
5201-10-25 52011025 52011025
5210-01-25 52100125 52100125
5211-11-25 52111125 52111125
5220-02-25 52200225 52200225
5221-12-25 52211225 52211225
5230-03-25 52300325 52300325
5240-04-25 52400425 52400425
5250-05-25 52500525 52500525
5260-06-25 52600625 52600625
5270-07-25 52700725 52700725
5280-08-25 52800825 52800825
5290-09-25 52900925 52900925
6001-10-06 60011006 60011006
6010-01-06 60100106 60100106
6011-11-06 60111106 60111106
6020-02-06 60200206 60200206
6021-12-06 60211206 60211206
6030-03-06 60300306 60300306
6040-04-06 60400406 60400406
6050-05-06 60500506 60500506
6060-06-06 60600606 60600606
6070-07-06 60700706 60700706
6080-08-06 60800806 60800806
6090-09-06 60900906 60900906
6101-10-16 61011016 61011016
6110-01-16 61100116 61100116
6111-11-16 61111116 61111116
6120-02-16 61200216 61200216
6121-12-16 61211216 61211216
6130-03-16 61300316 61300316
6140-04-16 61400416 61400416
6150-05-16 61500516 61500516
6160-06-16 61600616 61600616
6170-07-16 61700716 61700716
6180-08-16 61800816 61800816
6190-09-16 61900916 61900916
6201-10-26 62011026 62011026
6210-01-26 62100126 62100126
6211-11-26 62111126 62111126
6220-02-26 62200226 62200226
6221-12-26 62211226 62211226
6230-03-26 62300326 62300326
6240-04-26 62400426 62400426
6250-05-26 62500526 62500526
6260-06-26 62600626 62600626
6270-07-26 62700726 62700726
6280-08-26 62800826 62800826
6290-09-26 62900926 62900926
7001-10-07 70011007 70011007
7010-01-07 70100107 70100107
7011-11-07 70111107 70111107
7020-02-07 70200207 70200207
7021-12-07 70211207 70211207
7030-03-07 70300307 70300307
7040-04-07 70400407 70400407
7050-05-07 70500507 70500507
7060-06-07 70600607 70600607
7070-07-07 70700707 70700707
7080-08-07 70800807 70800807
7090-09-07 70900907 70900907
7101-10-17 71011017 71011017
7110-01-17 71100117 71100117
7111-11-17 71111117 71111117
7120-02-17 71200217 71200217
7121-12-17 71211217 71211217
7130-03-17 71300317 71300317
7140-04-17 71400417 71400417
7150-05-17 71500517 71500517
7160-06-17 71600617 71600617
7170-07-17 71700717 71700717
7180-08-17 71800817 71800817
7190-09-17 71900917 71900917
7201-10-27 72011027 72011027
7210-01-27 72100127 72100127
7211-11-27 72111127 72111127
7220-02-27 72200227 72200227
7221-12-27 72211227 72211227
7230-03-27 72300327 72300327
7240-04-27 72400427 72400427
7250-05-27 72500527 72500527
7260-06-27 72600627 72600627
7270-07-27 72700727 72700727
7280-08-27 72800827 72800827
7290-09-27 72900927 72900927
8001-10-08 80011008 80011008
8010-01-08 80100108 80100108
8011-11-08 80111108 80111108
8020-02-08 80200208 80200208
8021-12-08 80211208 80211208
8030-03-08 80300308 80300308
8040-04-08 80400408 80400408
8050-05-08 80500508 80500508
8060-06-08 80600608 80600608
8070-07-08 80700708 80700708
8080-08-08 80800808 80800808
8090-09-08 80900908 80900908
8101-10-18 81011018 81011018
8110-01-18 81100118 81100118
8111-11-18 81111118 81111118
8120-02-18 81200218 81200218
8121-12-18 81211218 81211218
8130-03-18 81300318 81300318
8140-04-18 81400418 81400418
8150-05-18 81500518 81500518
8160-06-18 81600618 81600618
8170-07-18 81700718 81700718
8180-08-18 81800818 81800818
8190-09-18 81900918 81900918
8201-10-28 82011028 82011028
8210-01-28 82100128 82100128
8211-11-28 82111128 82111128
8220-02-28 82200228 82200228
8221-12-28 82211228 82211228
8230-03-28 82300328 82300328
8240-04-28 82400428 82400428
8250-05-28 82500528 82500528
8260-06-28 82600628 82600628
8270-07-28 82700728 82700728
8280-08-28 82800828 82800828
8290-09-28 82900928 82900928
9001-10-09 90011009 90011009
9010-01-09 90100109 90100109
9011-11-09 90111109 90111109
9020-02-09 90200209 90200209
9021-12-09 90211209 90211209
9030-03-09 90300309 90300309
9040-04-09 90400409 90400409
9050-05-09 90500509 90500509
9060-06-09 90600609 90600609
9070-07-09 90700709 90700709
9080-08-09 90800809 90800809
9090-09-09 90900909 90900909
9101-10-19 91011019 91011019
9110-01-19 91100119 91100119
9111-11-19 91111119 91111119
9120-02-19 91200219 91200219
9121-12-19 91211219 91211219
9130-03-19 91300319 91300319
9140-04-19 91400419 91400419
9150-05-19 91500519 91500519
9160-06-19 91600619 91600619
9170-07-19 91700719 91700719
9180-08-19 91800819 91800819
9190-09-19 91900919 91900919
9201-10-29 92011029 92011029
9210-01-29 92100129 92100129
9211-11-29 92111129 92111129
9220-02-29 92200229 92200229
9221-12-29 92211229 92211229
9230-03-29 92300329 92300329
9240-04-29 92400429 92400429
9250-05-29 92500529 92500529
9260-06-29 92600629 92600629
9270-07-29 92700729 92700729
9280-08-29 92800829 92800829
9290-09-29 92900929 92900929
Total Palindrome days : 366