时间限制:C/C++ 1秒,其他语言2秒
空间限制:C/C++ 262144K,其他语言524288K
64bit IO Format: %lld

题目描述

定义一个数字为幸运数字当且仅当它的所有数位都是4或者7。
比如说,47、744、4都是幸运数字而5、17、467都不是。
定义next(x)为大于等于x的第一个幸运数字。给定l,r,请求出next(l) + next(l + 1) + ... + next(r - 1) + next(r)。

输入描述:

两个整数l和r (1 <= l <= r <= 1000,000,000)。

输出描述:

一个数字表示答案。

示例1

输入

2 7

输出

33

示例2

输入

7 7

输出

7

题解:由于1 <= l <= r <= 1000,000,000 ,所以在这里普通暴力肯定不行。4,7组合成最多也就1023种(包括4444444444),所以可以预处理一下,用数组储存。然后用二分查找的方法找大于等于l,r的对应下标,那么范围就缩小到了两个下标之差,在这个范围内,再用二分查找的方法找[l,r]中等于幸运数字的值,那么中间相隔乘以该幸运数字就是这段连续区间的答案,然后继续二分……

#include<bits/stdc++.h>
using namespace std;
long long s[1023]={4,7,44,47,74,77,444,447,474,477,744,747,774,777,4444,4447,4474,4477,4744,4747,4774,4777,7444,7447,7474,7477,7744,7747,7774,7777,44444,44447,44474,44477,44744,44747,44774,44777,47444,47447,47474,47477,47744,47747,47774,47777,74444,74447,74474,74477,74744,74747,74774,74777,77444,77447,77474,77477,77744,77747,77774,77777,444444,444447,444474,444477,444744,444747,444774,444777,447444,447447,447474,447477,447744,447747,447774,447777,474444,474447,474474,474477,474744,474747,474774,474777,477444,477447,477474,477477,477744,477747,477774,477777,744444,744447,744474,744477,744744,744747,744774,744777,747444,747447,747474,747477,747744,747747,747774,747777,774444,774447,774474,774477,774744,774747,774774,774777,777444,777447,777474,777477,777744,777747,777774,777777,4444444,4444447,4444474,4444477,4444744,4444747,4444774,4444777,4447444,4447447,4447474,4447477,4447744,4447747,4447774,4447777,4474444,4474447,4474474,4474477,4474744,4474747,4474774,4474777,4477444,4477447,4477474,4477477,4477744,4477747,4477774,4477777,4744444,4744447,4744474,4744477,4744744,4744747,4744774,4744777,4747444,4747447,4747474,4747477,4747744,4747747,4747774,4747777,4774444,4774447,4774474,4774477,4774744,4774747,4774774,4774777,4777444,4777447,4777474,4777477,4777744,4777747,4777774,4777777,7444444,7444447,7444474,7444477,7444744,7444747,7444774,7444777,7447444,7447447,7447474,7447477,7447744,7447747,7447774,7447777,7474444,7474447,7474474,7474477,7474744,7474747,7474774,7474777,7477444,7477447,7477474,7477477,7477744,7477747,7477774,7477777,7744444,7744447,7744474,7744477,7744744,7744747,7744774,7744777,7747444,7747447,7747474,7747477,7747744,7747747,7747774,7747777,7774444,7774447,7774474,7774477,7774744,7774747,7774774,7774777,7777444,7777447,7777474,7777477,7777744,7777747,7777774,7777777,44444444,44444447,44444474,44444477,44444744,44444747,44444774,44444777,44447444,44447447,44447474,44447477,44447744,44447747,44447774,44447777,44474444,44474447,44474474,44474477,44474744,44474747,44474774,44474777,44477444,44477447,44477474,44477477,44477744,44477747,44477774,44477777,44744444,44744447,44744474,44744477,44744744,44744747,44744774,44744777,44747444,44747447,44747474,44747477,44747744,44747747,44747774,44747777,44774444,44774447,44774474,44774477,44774744,44774747,44774774,44774777,44777444,44777447,44777474,44777477,44777744,44777747,44777774,44777777,47444444,47444447,47444474,47444477,47444744,47444747,47444774,47444777,47447444,47447447,47447474,47447477,47447744,47447747,47447774,47447777,47474444,47474447,47474474,47474477,47474744,47474747,47474774,47474777,47477444,47477447,47477474,47477477,47477744,47477747,47477774,47477777,47744444,47744447,47744474,47744477,47744744,47744747,47744774,47744777,47747444,47747447,47747474,47747477,47747744,47747747,47747774,47747777,47774444,47774447,47774474,47774477,47774744,47774747,47774774,47774777,47777444,47777447,47777474,47777477,47777744,47777747,47777774,47777777,74444444,74444447,74444474,74444477,74444744,74444747,74444774,74444777,74447444,74447447,74447474,74447477,74447744,74447747,74447774,74447777,74474444,74474447,74474474,74474477,74474744,74474747,74474774,74474777,74477444,74477447,74477474,74477477,74477744,74477747,74477774,74477777,74744444,74744447,74744474,74744477,74744744,74744747,74744774,74744777,74747444,74747447,74747474,74747477,74747744,74747747,74747774,74747777,74774444,74774447,74774474,74774477,74774744,74774747,74774774,74774777,74777444,74777447,74777474,74777477,74777744,74777747,74777774,74777777,77444444,77444447,77444474,77444477,77444744,77444747,77444774,77444777,77447444,77447447,77447474,77447477,77447744,77447747,77447774,77447777,77474444,77474447,77474474,77474477,77474744,77474747,77474774,77474777,77477444,77477447,77477474,77477477,77477744,77477747,77477774,77477777,77744444,77744447,77744474,77744477,77744744,77744747,77744774,77744777,77747444,77747447,77747474,77747477,77747744,77747747,77747774,77747777,77774444,77774447,77774474,77774477,77774744,77774747,77774774,77774777,77777444,77777447,77777474,77777477,77777744,77777747,77777774,77777777,444444444,444444447,444444474,444444477,444444744,444444747,444444774,444444777,444447444,444447447,444447474,444447477,444447744,444447747,444447774,444447777,444474444,444474447,444474474,444474477,444474744,444474747,444474774,444474777,444477444,444477447,444477474,444477477,444477744,444477747,444477774,444477777,444744444,444744447,444744474,444744477,444744744,444744747,444744774,444744777,444747444,444747447,444747474,444747477,444747744,444747747,444747774,444747777,444774444,444774447,444774474,444774477,444774744,444774747,444774774,444774777,444777444,444777447,444777474,444777477,444777744,444777747,444777774,444777777,447444444,447444447,447444474,447444477,447444744,447444747,447444774,447444777,447447444,447447447,447447474,447447477,447447744,447447747,447447774,447447777,447474444,447474447,447474474,447474477,447474744,447474747,447474774,447474777,447477444,447477447,447477474,447477477,447477744,447477747,447477774,447477777,447744444,447744447,447744474,447744477,447744744,447744747,447744774,447744777,447747444,447747447,447747474,447747477,447747744,447747747,447747774,447747777,447774444,447774447,447774474,447774477,447774744,447774747,447774774,447774777,447777444,447777447,447777474,447777477,447777744,447777747,447777774,447777777,474444444,474444447,474444474,474444477,474444744,474444747,474444774,474444777,474447444,474447447,474447474,474447477,474447744,474447747,474447774,474447777,474474444,474474447,474474474,474474477,474474744,474474747,474474774,474474777,474477444,474477447,474477474,474477477,474477744,474477747,474477774,474477777,474744444,474744447,474744474,474744477,474744744,474744747,474744774,474744777,474747444,474747447,474747474,474747477,474747744,474747747,474747774,474747777,474774444,474774447,474774474,474774477,474774744,474774747,474774774,474774777,474777444,474777447,474777474,474777477,474777744,474777747,474777774,474777777,477444444,477444447,477444474,477444477,477444744,477444747,477444774,477444777,477447444,477447447,477447474,477447477,477447744,477447747,477447774,477447777,477474444,477474447,477474474,477474477,477474744,477474747,477474774,477474777,477477444,477477447,477477474,477477477,477477744,477477747,477477774,477477777,477744444,477744447,477744474,477744477,477744744,477744747,477744774,477744777,477747444,477747447,477747474,477747477,477747744,477747747,477747774,477747777,477774444,477774447,477774474,477774477,477774744,477774747,477774774,477774777,477777444,477777447,477777474,477777477,477777744,477777747,477777774,477777777,744444444,744444447,744444474,744444477,744444744,744444747,744444774,744444777,744447444,744447447,744447474,744447477,744447744,744447747,744447774,744447777,744474444,744474447,744474474,744474477,744474744,744474747,744474774,744474777,744477444,744477447,744477474,744477477,744477744,744477747,744477774,744477777,744744444,744744447,744744474,744744477,744744744,744744747,744744774,744744777,744747444,744747447,744747474,744747477,744747744,744747747,744747774,744747777,744774444,744774447,744774474,744774477,744774744,744774747,744774774,744774777,744777444,744777447,744777474,744777477,744777744,744777747,744777774,744777777,747444444,747444447,747444474,747444477,747444744,747444747,747444774,747444777,747447444,747447447,747447474,747447477,747447744,747447747,747447774,747447777,747474444,747474447,747474474,747474477,747474744,747474747,747474774,747474777,747477444,747477447,747477474,747477477,747477744,747477747,747477774,747477777,747744444,747744447,747744474,747744477,747744744,747744747,747744774,747744777,747747444,747747447,747747474,747747477,747747744,747747747,747747774,747747777,747774444,747774447,747774474,747774477,747774744,747774747,747774774,747774777,747777444,747777447,747777474,747777477,747777744,747777747,747777774,747777777,774444444,774444447,774444474,774444477,774444744,774444747,774444774,774444777,774447444,774447447,774447474,774447477,774447744,774447747,774447774,774447777,774474444,774474447,774474474,774474477,774474744,774474747,774474774,774474777,774477444,774477447,774477474,774477477,774477744,774477747,774477774,774477777,774744444,774744447,774744474,774744477,774744744,774744747,774744774,774744777,774747444,774747447,774747474,774747477,774747744,774747747,774747774,774747777,774774444,774774447,774774474,774774477,774774744,774774747,774774774,774774777,774777444,774777447,774777474,774777477,774777744,774777747,774777774,774777777,777444444,777444447,777444474,777444477,777444744,777444747,777444774,777444777,777447444,777447447,777447474,777447477,777447744,777447747,777447774,777447777,777474444,777474447,777474474,777474477,777474744,777474747,777474774,777474777,777477444,777477447,777477474,777477477,777477744,777477747,777477774,777477777,777744444,777744447,777744474,777744477,777744744,777744747,777744774,777744777,777747444,777747447,777747474,777747477,777747744,777747747,777747774,777747777,777774444,777774447,777774474,777774477,777774744,777774747,777774774,777774777,777777444,777777447,777777474,777777477,777777744,777777747,777777774,777777777,4444444444};
int main()
{long long l,r;while(scanf("%lld%lld",&l,&r)==2){long long ans=0;int t=lower_bound(s,s+1023,l)-s;int tt=lower_bound(s,s+1023,r)-s;if(l==r)printf("%lld\n",s[t]);else{if(t==tt)ans=(r-l+1)*s[t];else{int mid,x=l,y=r;for(int i=t;i<=tt;i++){y=r;int flag=1;while(x<=y){mid=x+(y-x)/2;if(mid<s[i])x=mid+1;else if(mid>s[i])y=mid-1;else{flag=0;break;}}if(flag) ans+=(r-l+1)*s[i];elseans+=(mid-l+1)*s[i];l=s[i]+1;}}printf("%lld\n",ans);}}return 0;
}

B-幸运数字II (打表+二分查找)相关推荐

  1. LeetCode-878. 第 N 个神奇数字【数学,二分查找,找规律】

    LeetCode-878. 第 N 个神奇数字[数学,二分查找,找规律] 题目描述: 解题思路一:二分答案+容斥原理.给定一个上下界,然后依次增大下界或者减小上界,直到只剩一个答案.容斥原理是,加上两 ...

  2. Leetcode 129求根节点到叶节点数字之和、104二叉树的最大深度、8字符串转换整数(atoi)、82删除排序链表中的重复元素II、204二分查找、94二叉树的中序遍历、144二叉树的前序遍历

    Top1:Leetcode 129求根节点到叶节点数字之和 官方题解:https://leetcode.cn/problems/sum-root-to-leaf-numbers/solution/qi ...

  3. ssl1125-集合【哈希表二分查找+快排】

    前言 今天学哈希表,然后就第一节晚修赶快写完作业就上了做题了,然后就做完了这道题get√. 正题 题目 给出两个集合: A是B的一个真子集,输出"A is a proper subset o ...

  4. 【牛客】幸运数字II题解

    原题链接 题目描述 定义一个数字为幸运数字当且仅当它的所有数位都是4或者7. 比如说,47.744.4都是幸运数字而5.17.467都不是. 定义next(x)为大于等于x的第一个幸运数字.给定l,r ...

  5. LeetCode 1751. 最多可以参加的会议数目 II(DP + 二分查找)

    文章目录 1. 题目 2. 解题 1. 题目 给你一个 events 数组,其中 events[i] = [startDayi, endDayi, valuei] ,表示第 i 个会议在 startD ...

  6. Python数据结构——对有序表二分查找

    list= [1, 5, 6, 9, 10, 51, 62, 65, 70] 查找5时: [1, 5, 6, 9, 10, 51, 62, 65, 70]        low=0    high=9 ...

  7. 幸运数字II(二进制问题)

    时间限制: 1 Sec 内存限制: 128 MB 题目描述 数字4和7是幸运数字,而其他的都不是幸运数字.一个整数是幸运数字,当且仅当它的十进制表示只包含幸运数字. 现在让你给出第K大的幸运数字. 输 ...

  8. LeetCode 729. 我的日程安排表 I(set 二分查找)

    文章目录 1. 题目 2. 解题 2.1 set 二分查找 2.2 差分思想 1. 题目 实现一个 MyCalendar 类来存放你的日程安排.如果要添加的时间内没有其他安排,则可以存储这个新的日程安 ...

  9. java数组线性查找_数组查找: 线性查找与二分查找

    前言 从数组中查找你需要的数据,是一个很常见的需求,那么当你查找所需数据时,用什么方法查找速度最快? 本文将通过图文形式,详细讲解线性查找与二分查找,并用JavaScript将其实现,欢迎各位感兴趣的 ...

最新文章

  1. android 刷windows10,微软计划在Android机上刷Windows 10
  2. 2018移动端页面适配-自适应最新方案直接写px--------通过gulp工作流搭建一体化的移动端开发环境
  3. [vue] 你了解vue的diff算法吗?
  4. 2019阿里巴巴技术面试题集锦(含答案)
  5. 在线笔记存代码_李宏毅《机器学习》完整版笔记发布
  6. firewalld的配置和使用
  7. WP8多分辨率解决方案
  8. ad18 bell封装,AD元件库中常用元件
  9. Labelme标注软件下载安装教程
  10. 紫书刷题记录 UVa12100 打印队列
  11. 双引号后面要加句号吗_双引号该怎么加?是加在句号或者分号后面还是前面
  12. linux nginx启动脚本,Nginx启动脚本大家来找茬
  13. 自学iOS开发的一些经验
  14. android手机图标 足球球星,C罗梅西最抢眼 足球巨星们都用什么手机
  15. Oracle EBS财务模块(三)总账功能
  16. PAT_乙级_1008_筱筱
  17. 域名的DA值和PA值用什么工具查询?
  18. 解决图片按顺序加载问题
  19. HTTPS网站提示“此网站无法提供安全连接”
  20. 2023第三方应用苹果电脑磁盘读写工具Tuxera NTFS

热门文章

  1. Android输入法开发之Android SDK Sample—SoftKeyboard
  2. 5. 阿里巴巴程序员开发手册黄山版
  3. JSONArray与JSONObject
  4. CPU 风扇清理灰尘加油全过程图解
  5. win7卡在正在启动windows界面_分享一下WIN7系统下运行红警2的方法
  6. python学什么教学_学习python的几个小技巧
  7. 原因为何?日本机器人饭店Henn-na开除半数机器人
  8. 【小白之路-1】详解ESP8266 ESP-01SRealy继电器模块天猫精灵语音控制实现(含微信配网及新手防坑提示)
  9. 2011年国赛B题论文研读
  10. QQ个人中心功能测试点