PUZZLEUP 2014

newkid · 发表于 2014-9-17 21:25

No: 08 September 17, 2014

Adjacent Digits

How many positive 10-digit integers are there with the property that for each digit N, the number of adjacent N's is at most N?

(Examples: 1223334444, 7777777822, 5999999999, 3434343434)

相邻数字
有多少个10位的正整数具备这样的属性：对于每个数字N, 相邻的N的个数不超过N?

(例如: 1223334444, 7777777822, 5999999999, 3434343434)

即相邻的2最多两个，相邻的3最多3个，相邻的7最多7个,...被隔断后再次出现的另外计算。按这规则0不应该出现。

newkid · 发表于 2014-9-17 21:26

第七题的章发给peter,要哪个?

〇〇 · 发表于 2014-9-17 21:32

newkid 发表于 2014-9-17 21:25
No: 08 September 17, 2014

Adjacent Digits

只要删除不具有此属性的就知道了

〇〇 · 发表于 2014-9-17 21:34

〇〇发表于 2014-9-17 21:32
只要删除不具有此属性的就知道了

select * from x where not exist
select 1 from bad_dict where instr(x,badstr)>0)

newkid · 发表于 2014-9-17 21:39

〇〇发表于 2014-9-17 21:34
select * from x where not exist
select 1 from bad_dict where instr(x,badstr)>0)

总数有9^10，JOIN用不上只能FILTER, 你跑跑看？

〇〇 · 发表于 2014-9-17 22:14

〇〇发表于 2014-9-17 21:34
select * from x where not exist
select 1 from bad_dict where instr(x,badstr)>0)

穷举法用c都跑不出来
，看来要及时调步
#include <stdio.h>
int main()
{
char s[10][10]={"0","11","222","3333","44444","555555","6666666","77777777","888888888"};
char s1[11];
int x,i,c=0;
for(x=1223334444;x<9999999999;x++)
for(i=0;i<9;i++)
{
if (strstr(itoa(x,s1,10),s)!=NULL)continue;
}
c++;
printf("%d\n",c);
return 1;
}