【模拟/字符串】DRM Messages

DRM Encryption is a new kind of encryption. Given an encrypted string (which we’ll call a DRM
message), the decryption process involves three steps: Divide, Rotate and Merge. This process is
described in the following example with the DRM message “EWPGAJRB”:
Divide — First, divide the message in half to “EWPG” and “AJRB”.
Rotate — For each half, calculate its rotation value by summing up the values of each character
(A = 0, B = 1, . . . Z = 25). The rotation value of “EWPG” is 4 + 22 + 15 + 6 = 47. Rotate each
character in “EWPG” 47 positions forward (wrapping from Z to A when necessary) to obtain the
new string “ZRKB”. Following the same process on “AJRB” results in “BKSC”.
Merge — The last step is to combine these new strings (“ZRKB” and “BKSC”) by rotating each character
in the first string by the value of the corresponding character in the second string. For the first
position, rotating ‘Z’ by ‘B’ means moving it forward 1 character, which wraps it around to ‘A’.
Continuing this process for every character results in the final decrypted message, “ABCD”.
Input
The input file contains several test cases, each of them as described below.
The input contains a single DRM message to be decrypted. All characters in the string are uppercase
letters and the string’s length is even and ≤ 15000.
Output
For each test case, display the decrypted DRM message.
Sample Input
EWPGAJRB
UEQBJPJCBUDGBNKCAHXCVERXUCVK
Sample Output
ABCD
ACMECNACONTEST

【思维/模拟】Self Numbers

In 1949 the Indian mathematician D.R. Kaprekar discovered a class of numbers called self-numbers. For any positive integer n, define d(n) to be n plus the sum of the digits of n. (The d stands for digitadition, a term coined by Kaprekar.) For example, d(75) = 75 + 7 + 5 = 87. Given any positive integer n as a starting point, you can construct the infinite increasing sequence of integers n, d(n), d(d(n)), d(d(d(n))), …. For example, if you start with 33, the next number is 33 + 3 + 3 = 39, the next is 39 + 3 + 9 = 51, the next is 51 + 5 + 1 = 57, and so you generate the sequence
33, 39, 51, 57, 69, 84, 96, 111, 114, 120, 123, 129, 141, …The number n is called a generator of d(n). In the sequence above, 33 is a generator of 39, 39 is a generator of 51, 51 is a generator of 57, and so on. Some numbers have more than one generator: for example, 101 has two generators, 91 and 100. A number with no generators is a self-number. There are thirteen self-numbers less than 100: 1, 3, 5, 7, 9, 20, 31, 42, 53, 64, 75, 86, and 97.

Write a program to output all positive self-numbers less than or equal 1000000 in increasing order, one per line.

【区间查询】Crawling in process

Given an array with n integers, and you are given two indices i and j (i ≠ j) in the array. You have to find two integers in the range whose difference is minimum. You have to print this value. The array is indexed from 0 to n-1.

codeforces-1037D Berland Fair

XXI Berland Annual Fair is coming really soon! Traditionally fair consists of n booths, arranged in a circle. The booths are numbered through n clockwise with n being adjacent to 1. The i-th booths sells some candies for the price of ai burles per item. Each booth has an unlimited supply of candies. 继续阅读codeforces-1037D Berland Fair