bzoj1026: [SCOI2009]windy数

#include<cstdio>
#include<cstring>
#include<iostream>
#include<algorithm>
using namespace std;
#define rep(i,s,t) for(int i=s;i<=t;i++)
#define dwn(i,s,t) for(int i=s;i>=t;i--)
#define clr(x,c) memset(x,c,sizeof(x))
int read(){
	int x=0;char c=getchar();
	while(!isdigit(c)) c=getchar();
	while(isdigit(c)) x=x*10+c-‘0‘,c=getchar();
	return x;
}

int as(int x){
	return x>=0?x:-x;
}
int dp[12][10],bit[12];
void init(){
	rep(i,0,9) dp[1][i]=1;
	rep(i,2,11) rep(j,0,9) rep(k,0,9) if(as(j-k)>=2) dp[i][j]+=dp[i-1][k];
}

int work(int x){
	int tmp=x,cnt=0,ans=0;
	while(tmp) bit[++cnt]=tmp%10,tmp/=10;
	rep(i,1,cnt-1) rep(j,1,9) ans+=dp[i][j];
	rep(i,1,bit[cnt]-1) ans+=dp[cnt][i];
	dwn(i,cnt-1,1){
		rep(j,0,bit[i]-1) if(as(j-bit[i+1])>=2) ans+=dp[i][j];
		if(as(bit[i]-bit[i+1])<2) break;
	}
	return ans;
}

int main(){
	int A=read(),B=read();init();
	printf("%d\n",work(B+1)-work(A));
	return 0;
}