# [SCOI2009]windy数 BZOJ1026 数位dp

## 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，

## 输入输出样例

1 10

9

25 50


20


## 说明

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

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstdlib>
#include<cstring>
#include<string>
#include<cmath>
#include<map>
#include<set>
#include<vector>
#include<queue>
#include<bitset>
#include<ctime>
#include<time.h>
#include<deque>
#include<stack>
#include<functional>
#include<sstream>
//#include<cctype>
//#pragma GCC optimize(2)
using namespace std;
#define maxn 100005
#define inf 0x7fffffff
//#define INF 1e18
#define rdint(x) scanf("%d",&x)
#define rdllt(x) scanf("%lld",&x)
#define rdult(x) scanf("%lu",&x)
#define rdlf(x) scanf("%lf",&x)
#define rdstr(x) scanf("%s",x)
#define mclr(x,a) memset((x),a,sizeof(x))
typedef long long  ll;
typedef unsigned long long ull;
typedef unsigned int U;
#define ms(x) memset((x),0,sizeof(x))
const long long int mod = 100000007;
#define Mod 1000000000
#define sq(x) (x)*(x)
#define eps 1e-5
typedef pair<int, int> pii;
#define pi acos(-1.0)
//const int N = 1005;
#define REP(i,n) for(int i=0;i<(n);i++)
typedef pair<int, int> pii;

inline int rd() {
int x = 0;
char c = getchar();
bool f = false;
while (!isdigit(c)) {
if (c == '-') f = true;
c = getchar();
}
while (isdigit(c)) {
x = (x << 1) + (x << 3) + (c ^ 48);
c = getchar();
}
return f ? -x : x;
}

ll gcd(ll a, ll b) {
return b == 0 ? a : gcd(b, a%b);
}
int sqr(int x) { return x * x; }

/*ll ans;
ll exgcd(ll a, ll b, ll &x, ll &y) {
if (!b) {
x = 1; y = 0; return a;
}
ans = exgcd(b, a%b, x, y);
ll t = x; x = y; y = t - a / b * y;
return ans;
}
*/

ll dp[20][20], ans;
int a[maxn];
int len;
ll l, r;

ll dfs(int pos, int pre, int lead, int limit) {
if (pos > len)return 1;
if (!limit&&dp[pos][pre] != -1)return dp[pos][pre];
ll res = 0;
int up = limit ? a[len - pos + 1] : 9;
for (int i = 0; i <= up; i++) {
if (abs(i - pre) < 2)continue;
if (lead&&i == 0)res += dfs(pos + 1, -2, 1, limit&&i == up);
else res += dfs(pos + 1, i, 0, limit&i == up);
}
if (!limit && !lead)dp[pos][pre] = res;
return res;
}

ll sol(ll x) {
len = 0;
while (x)a[++len] = x % 10, x /= 10;
mclr(dp, -1);
return dfs(1, -2, 1, 1);
}

int main()
{
//	ios::sync_with_stdio(0);
rdllt(l); rdllt(r);
cout << (ll)sol(r) - (ll)sol(l - 1) << endl;
return 0;
}


posted @ 2019-02-08 09:48  NKDEWSM  阅读(103)  评论(0编辑  收藏