题目大意 考虑自然数构成的序列 $a$:$01234567891011\dots$,序列下标从 $0$ 开始,即 $a_0 =0, a_1 = 1$ . 求 $a_n$($0\le n\le 10^{18}$). 解法 设 $a_n$ 所在的数字为 $x(n)$ . 首先不难求出 $x(n)$ 的位数, 设其为 $k$ . 从而可以求出 $x(n)$ 是第几个 $k$ 位数,这样也就求出了 $x(n)$ . 设 $x(n)$ 是第 $i$($i\ge 1$)个 $k$ 位数,则有 $$ i =…

Description You are given n constant integers c[1], c[2], ..., c[n] and an integer k. You are to assign values to 2k integer variables, x[1], x[2], ..., x[k], y[1], y[2], ..., y[k], such that, (1) For each 1 ≤ i ≤ k, x[i] ≤ y[i] holds, (2) For each 1…

hihoCoder #1432 : JiLi Number(吉利数) 时间限制:1000ms 单点时限:1000ms 内存限制:256MB Description - 题目描述 Driver Ji likes the digit "1". He has an accumulator which shows the sum of input number. He lists all of positive number no more than N and starts counting…

Description In the city, there is a one-way straight highway starts from the northern end, traverses the whole city southward, and finishes at the southern end. Due to some financial difficulties, there is only one lane on this highway, which means t…

The top 100 papers Nature explores the most-cited research of all time. The discovery of high-temperature superconductors, the determination of DNA’s double-helix structure, the first observations that the expansion of the Universe is accelerating —…

If we take 47, reverse and add, 47 + 74 = 121, which is palindromic. Not all numbers produce palindromes so quickly. For example, 349 + 943 = 1292, 1292 + 2921 = 4213 4213 + 3124 = 7337 That is, 349 took three iterations to arrive at a palindrome. Al…

http://hihocoder.com/problemset/problem/1873 时间限制:1000ms 单点时限:1000ms 内存限制:512MB 描述 A small frog wants to get to the other side of a river. The frog is initially located at one bank of the river (position 0) and wants to get to the other bank (positio…

在Java位运算总结-leetcode题目博文中总结了Java提供的按位运算操作符,今天又碰到LeetCode中一道按位操作的题目 Given a range [m, n] where 0 <= m <= n <= 2147483647, return the bitwise AND of all numbers in this range, inclusive. For example, given the range [5, 7], you should return 4. 题意:…

Sum of Consecutive Prime Numbers Time Limit: 1000MS   Memory Limit: 65536K Total Submissions: 20050   Accepted: 10989 Description Some positive integers can be represented by a sum of one or more consecutive prime numbers. How many such representatio…

You are given two linked lists representing two non-negative numbers. The most significant digit comes first and each of their nodes contain a single digit. Add the two numbers and return it as a linked list. You may assume the two numbers do not con…