Problem F. Fibonacci SystemTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://acm.hust.edu.cn/vjudge/contest/view.action?cid=86821#problem/B Description Little John studies numeral systems. After learning all about fixed-base systems, he became inte…

Problem F. Door LockTime Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100500/attachments Description It was a beautiful night at Yekaterinburg, the sky was crystal clear with no clouds, and the view of the moon and the stars was…

Problem F "Folding" Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/gym/100002 Description Bill is trying to compactly represent sequences of capital alphabetic characters from 'A' to 'Z' by folding repeating subsequences insid…

D. Beautiful numbers Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/55/problem/D Description Volodya is an odd boy and his taste is strange as well. It seems to him that a positive integer number is beautiful if and only i…

(https://www.pixiv.net/member_illust.php?mode=medium&illust_id=65608478) Problem Description For a decimal number x with n digits (AnAn-1An-2 ... A2A1), we define its weight as F(x) = An * 2n-1 + An-1 * 2n-2 + ... + A2 * 2 + A1 * 1. Now you are given…

http://codeforces.com/gym/100623/attachments 题意:问1到n里面有多少个数满足:本身被其各个数位加起来的和整除.例如120 % 3 == 0,111 % 3 == 0,都算. 思路:老是写不出数位DP... 因为n最大为12位,所以取模的数最大可以是9*12 == 108,因此枚举这个模. dfs记录的状态有:pos, sum, mod, remain, flag. pos代表枚举到第几位, sum代表数位之和, mod代表当前枚举的模, remain…

While doing some spring cleaning, Daniel found an old calculator that he loves so much. However, it seems like it is broken. When he tries to compute 1+31+3 using the calculator, he gets 22 instead of 44. But when he tries computing 1+41+4, he gets t…

For a decimal number x with n digits (A nA n-1A n-2 ... A 2A 1), we define its weight as F(x) = A n * 2 n-1 + A n-1 * 2 n-2 + ... + A 2 * 2 + A 1 * 1. Now you are given two numbers A and B, please calculate how many numbers are there between 0 and B,…

http://acm.hdu.edu.cn/showproblem.php?pid=4389 题意 为[A,B] 区间内的数能刚好被其位数和整除的数有多少个. 分析 典型的数位dp...比赛时想不出状态怎么构造,太弱了我. 言归正传,数位和有81种状态,怎么判断当前数字是否被整除呢?可以利用余数的思想,至此,定义状态dp[pos][sum][mod][res]表示前pos位的数位和为sum模mod的结果为res的个数,采用记忆化搜索比较简洁. #include<iostream> #inclu…

这道题还是关于数位DP的板子题 数位DP有一个显著的特征,就是求的东西大概率与输入关系不大,理论上一般都是数的构成规律 然后这题就是算一个\( F(A) \)的公式值,然后求\( \left [ 0 ,  B \right ] \)区间内\( F(x) \)不大于\( F(A) \)的数的个数 所以由数据范围很容易得到计算出最大值不会超过4600 然后我们设状态\( dp[10][4600][4600] \)表示不同\( F(A) \)取值下的第\( pos \)个位置的值总和为 \( sumx…