P2657 [SCOI2009]windy数

Posted 2020-11-05 five20

题目描述

windy定义了一种windy数。不含前导零且相邻两个数字之差至少为2的正整数被称为windy数。 windy想知道，

在A和B之间，包括A和B，总共有多少个windy数？

输入输出格式

输入格式：

包含两个整数，A B。

输出格式：

一个整数

输入输出样例

输入样例#1： 

1 10

输出样例#1： 

9

输入样例#2： 

25 50

输出样例#2： 

20

说明

100%的数据，满足 1 <= A <= B <= 2000000000 。

 

Solution：

　　本题显然数位$DP$，暂时不会（留着填坑～）。

　　提供打表的思路，先线下每$10^6$个处理一次，统计出$2000$个答案（前缀和$sum[i]$表示$1$到$i*10^6$中满足条件的个数）。

　　那么查询时就直接瞎搞模拟，最多计算$10^6$次。

打表代码：

 

 1 /**************************************************************
 2     Problem: 1026
 3     User: five20
 4     Language: C++
 5     Result: Accepted
 6     Time:256 ms
 7     Memory:1296 kb
 8 ****************************************************************/
 9  
10 #include<iostream>
11 #include<cstdio>
12 #include<algorithm>
13 #include<cmath>
14 #define For(i,a,b) for(int (i)=(a);(i)<=(b);(i)++)
15 using namespace std;
16 const int N=1e6+5;
17 int ans,a,b,sum[2005]={0, 202174, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 155315, 136131, 138503, 138214, 138252, 138252, 138214, 138503, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 138503, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 0, 0, 0, 138214, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 0, 0, 0, 138252, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 0, 0, 0, 138252, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 0, 0, 0, 138214, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 0, 0, 0, 138503, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 0, 0, 0, 136131, 155315, 155315, 136131, 138503, 138214, 138252, 138252, 0, 0, 0, 155315, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
18 inline void check(int x){
19     if(x<=9){ans++;return;}
20     int a=x,b=-5;
21     while(a){
22         if(abs(a%10-b)<2)return;
23         b=a%10;a=a/10;
24     }
25     ans++;
26 }
27 int main(){
28     cin>>a>>b;
29     if(b-a<=1000000){
30         For(i,a,b)check(i);
31         cout<<ans;
32         return 0;
33     }
34     int p=ceil(a*1.0/1000000),q=floor(b*1.0/1000000);
35     For(i,1,2000)sum[i]+=sum[i-1];
36     ans+=sum[q]-sum[p];
37     if(!ans)ans++;
38     p=p*1000000,q=q*1000000;
39     if(a!=p)
40     For(i,a,p-1)check(i);
41     if(b!=q)
42     For(i,q+1,b)check(i);
43     cout<<ans;
44     return 0;
45 }