windy数

#include<bits/stdc++.h>
using namespace std;
const int MAXN = 64;
int dp[MAXN][MAXN];
vector<int> dim;
int dfs(int x, int st, int lim) {
    if (!x) return 1;
    if (!lim && dp[x][st] != -1) return dp[x][st];
    int up = lim ? dim[x] : 9, ret = 0;
    for (int i = 0; i <= up; i++) {
        if (abs(i - st) < 2) continue;//绝对值之差小于2不能选
        if (st == 11 && i == 0)//前导零状态
            ret += dfs(x - 1, 11, lim & (i == up));
        else//正常状态
            ret += dfs(x - 1, i, lim & (i == up));
    }
    if (!lim) dp[x][st] = ret;//如果当前限制状态量为0
    return ret;//返回当前答案
}
int solve(int x) {
    memset(dp, -1, sizeof(dp));
    dim.clear();
    dim.push_back(-1);
    while (x) {
        dim.push_back(x % 10); x /= 10;
    }
    return dfs(dim.size() - 1, 11, 1);//从最高位开始枚举，初始状态限制标记量标为1
}
int main() {
    int A, B;
    cin >> A >> B;
    cout << solve(B) - solve(A - 1) << endl;
    return 0;
}