[暑假集训--数位dp]hdu5787 K-wolf Number

Posted 2020-10-01 zhber

Alice thinks an integer x is a K-wolf number, if every K adjacent digits in decimal representation of x is pairwised different.
Given (L,R,K), please count how many K-wolf numbers in range of L,RL,R .

Input

The input contains multiple test cases. There are about 10 test cases.

Each test case contains three integers L, R and K.

1≤L≤R≤1e18
2≤K≤52≤K≤5

Output

For each test case output a line contains an integer.

Sample Input

1 1 2
20 100 5

Sample Output

1
72

 

 

问有多少个数，任意连续k位都不相同

记一下前k-1位，有没有前导零

 1 #include<cstdio>
 2 #include<iostream>
 3 #include<cstring>
 4 #include<cstdlib>
 5 #include<algorithm>
 6 #include<cmath>
 7 #include<queue>
 8 #include<deque>
 9 #include<set>
10 #include<map>
11 #include<ctime>
12 #define LL long long
13 #define inf 0x7ffffff
14 #define pa pair<int,int>
15 #define mkp(a,b) make_pair(a,b)
16 #define pi 3.1415926535897932384626433832795028841971
17 using namespace std;
18 inline LL read()
19 {
20     LL x=0,f=1;char ch=getchar();
21     while(ch<‘0‘||ch>‘9‘){if(ch==‘-‘)f=-1;ch=getchar();}
22     while(ch>=‘0‘&&ch<=‘9‘){x=x*10+ch-‘0‘;ch=getchar();}
23     return x*f;
24 }
25 LL n,len,l,r,k;
26 LL f[20][2300][2];
27 int zhan[110];
28 int d[110];
29 inline LL dfs(int now,int stat,int lead,int fp)
30 {
31     if (now==1)return 1;
32     if (!fp&&f[now][stat][lead]!=-1)return f[now][stat][lead];
33     LL ans=0,mx=fp?d[now-1]:9;
34     int lst=0;
35     for(int i=now;i<=min(now+k-2,len);i++)if (zhan[i]!=-1)lst|=1<<zhan[i];
36     for (int i=0;i<=mx;i++)
37     {
38         if (lst&(1<<i))continue;
39         if (i==0&&lead&&now-1!=1)zhan[now-1]=-1;else zhan[now-1]=i;
40         if (zhan[now-1]!=-1)lst|=(1<<i);
41         ans+=dfs(now-1,lst,lead&&i==0&&now-1!=1,fp&&(i==d[now-1]));
42         if (zhan[now-1]!=-1)lst-=(1<<i);
43     }
44     if (!fp)f[now][stat][lead]=ans;
45     return ans;
46 }
47 inline LL calc(LL x)
48 {
49     if (!x)return 1;
50     LL xxx=x;
51     len=0;
52     while (xxx)
53     {
54         d[++len]=xxx%10;
55         xxx/=10;
56     }
57     LL sum=0;
58     for (int i=0;i<=d[len];i++)
59     {
60         if (i==0&&len!=1)zhan[len]=-1;else zhan[len]=i;
61         if (zhan[len]!=-1)sum+=dfs(len,1<<zhan[len],zhan[len]==-1,i==d[len]);
62         else sum+=dfs(len,0,zhan[len]==-1,i==d[len]);
63         zhan[len]=-1;
64     }
65     return sum;
66 }
67 main()
68 {
69     while (~scanf("%lld%lld%lld",&l,&r,&k))
70     {
71         memset(f,-1,sizeof(f));
72         printf("%lld\n",calc(r)-calc(l-1));
73     }
74 }

hdu 5787