C++ 代码

#include <bits/stdc++.h>
using namespace std;

const int N = 40;

int arr[N];
int dp[N][N];

int dfs(int pos, int pre, int limit){
    if(!pos) return 1;
    if(!limit && dp[pos][pre] != -1) return dp[pos][pre];
    int up = limit ? arr[pos] : 9;
    int ans = 0;
    for(int i = 0;i <= up;++i)
        if(i == 4 || (pre == 6 && i == 2)) continue;
        else 
            ans += dfs(pos-1, i, limit && (i == up));
    if(!limit) dp[pos][pre] = ans;
    return ans;
}

int solve(int x){
    int cnt = 0;
    while(x) arr[++cnt] = x % 10, x /= 10;
    memset(dp, -1, sizeof dp);
    return dfs(cnt, -1, 1);
}

int main(){
    int l, r;
    while(cin >> l >> r, l || r){
        cout << solve(r) - solve(l-1) << endl;
    }
}