题意:给定x.y.为[x,y]之间有多少个数的偶数位和减去奇数位和等于一. 个位是第一位. 样例: 10=1-0=1 所以10是这种数 思路:数位dp[i][sum][ok] i位和为sum 是否含有前导0. 然后就是由于有负数 所以依据范围把0设置为100 然后最后和等于101则为所求的数. 代码: #include"cstdlib" #include"cstdio" #include"cstring" #include"cmath&…

题目 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 if it is divisible by each of its nonzero digits. We will not argue with this and just count the quantity of beautiful…

原题直通车: HDU  4722  Good Numbers 题意: 求区间[a,b]中各位数和mod 10==0的个数. 代码: #include<iostream> #include<cstdio> #include<cstring> #include<cmath> using namespace std; int f[20]; long long work(long long x){ long long ret=0, u=x; int t=0, s=0…

题目链接:http://www.spoj.com/problems/BALNUM/en/ Time limit: 0.123s Source limit: 50000B Memory limit: 1536MB Balanced numbers have been used by mathematicians for centuries. A positive integer is considered a balanced number if: 1)      Every even digit…

题目:http://www.spoj.com/problems/BALNUM/en/ 题意:找出区间[A, B]内所有奇数字出现次数为偶数,偶数字出现次数为计数的数的个数. 分析: 明显的数位dp题,首先,只有3种状态(0:没出现过, 1:数字出现奇数次, 2:数字出现偶数次),所以, 0~9 出现的次数就可以用3进制表示,最大的数就是 310 ,那么我们就可以把1019 哈希到310 内了.其中,我们可以假设: (0:30  ,1:31 , 2:32 , .... , 9: 39 ) 当第一次…

BIGSEQ - Sequence You are given the sequence of all K-digit binary numbers: 0, 1,..., 2K-1. You need to fully partition the sequence into M chunks. Each chunk must be a consecutive subsequence of the original sequence. Let Si (1 ≤ i ≤ M) be the total…

SORTBIT - Sorted bit squence no tags Let's consider the 32 bit representation of all integers i from m up to n inclusive (m ≤ i ≤ n; m × n ≥ 0, -2^31 ≤ m ≤ n ≤ 2^31-1). Note that a negative number is represented in 32 bit Additional Code. That is the…

SPOJ - BALNUM 题意: Balanced Numbers:数位上的偶数出现奇数次,数位上的奇数出现偶数次(比如2334, 2出现1次,4出现1次,3出现两次,所以2334是 Balanced Numbers) ,求一个区间内有多少Balanced Numbers. 解题思路:看题很容易想到数位dp,但是怎么记录某数字出现的次数呢?由于某数字出现的次数只与奇偶有关,与大小没有关系,所以我们可以分别用0,1,2来表示某数字没有出现,出现奇数次,出现偶数次,然后就可以用三进制来记录所有数字…

[BZOJ1662][Usaco2006 Nov]Round Numbers 圆环数 Description 正如你所知,奶牛们没有手指以至于不能玩"石头剪刀布"来任意地决定例如谁先挤奶的顺序.她们甚至也不能通过仍硬币的方式. 所以她们通过"round number"竞赛的方式.第一头牛选取一个整数,小于20亿.第二头牛也这样选取一个整数.如果这两个数都是 "round numbers",那么第一头牛获胜,否则第二头牛获胜. 如果一个正整数N的二…

题目传送门 /* 找规律/数位DP:我做的时候差一点做出来了,只是不知道最后的 is_one () http://www.cnblogs.com/crazyapple/p/3315436.html 数位DP:http://blog.csdn.net/libin56842/article/details/11580497 */ #include <cstdio> #include <iostream> #include <algorithm> #include <c…