题意:已知n个数,第i个为ci,给定一个数x mod ci的结果,再给点一个k,问能不能知道x mod k的值? 分析:刚看题目的我一脸蒙蔽,对题意有点不理解,能的情况似乎有很多,我该从哪里下手呢? 先从不能的情况来看,可以知道,如果不能知道x mod k的值,当且仅当有两个解x1,x2, x1 ≡ x2(mod ci)x1 ≢ x2 (mod k) 左边这个是不同余的意思, 为什么是这样的呢?因为题目中说x mod k的值是唯一的,我们却会出现两个满足题意的x值 mod k的值不同,这就…

一.先是一些整除的性质: •整除:若a=bk,其中a,b,k都是整数,则b整除a,记做b|a. •也称b是a的约数(因数),a是b的倍数 •显而易见的性质: •1整除任何数,任何数都整除0 •若a|b,a|c,则a|b+c, a|b-c •若a|b,则对任意整数c,a|bc •传递性:若a|b,b|c,则a|c 例1: •例题:[CF 762A]k-th divisor •求n的第k小的约数.如果不存在输出-1 •1 ≤ n ≤ 10^15, 1 ≤ k ≤ 10^9 分析:这道题显然不能用O(…

B. Remainders Game time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Today Pari and Arya are playing a game called Remainders. Pari chooses two positive integer x and k, and tells Arya k but…

D - Remainders Game Description Today Pari and Arya are playing a game called Remainders. Pari chooses two positive integer x and k, and tells Arya k but not x. Arya have to find the value . There are n ancient numbersc1,  c2, ..., cn and Pari has to…

E. Sum of Remainders time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Calculate the value of the sum: n mod 1 + n mod 2 + n mod 3 + ... + n mod m. As the result can be very large, you shoul…

E. Sum of Remainders 题目连接: http://www.codeforces.com/contest/616/problem/E Description The only line contains two integers n, m (1 ≤ n, m ≤ 1013) - the parameters of the sum. input The only line contains two integers n, m (1 ≤ n, m ≤ 1013) - the para…

题目链接: 题目 D. Remainders Game time limit per test 1 second memory limit per test 256 megabytes 问题描述 Today Pari and Arya are playing a game called Remainders. Pari chooses two positive integer x and k, and tells Arya k but not x. Arya have to find the v…

616E Sum of Remainders Calculate the value of the sum: n mod 1 + n mod 2 + n mod 3 + - + n mod m. As the result can be very large, you should print the value modulo 109 + 7 (the remainder when divided by 109 + 7). The modulo operator a mod b stands f…

题目连接:Equalize the Remainders 题意:n个数字,对m取余有m种情况,使得每种情况的个数都为n/m个(保证n%m=0),最少需要操作多少次? 每次操作可以把某个数字+1.输出最少操作次数,和操作后的序列(可以输出任意一种). 题解:用一个set来维护所有余数x(当前余数为x的数个数没凑够n/m个),对于每个数假设这个数的余数为t,当余数为t的数个数没凑够n/m时那这个数就不需要改变,如果已经凑够了,那就在set中找到第一个大于等于t的数(注意这里t可能比set中最大数的还…

D. Remainders Game 题目连接: http://www.codeforces.com/contest/688/problem/D Description Today Pari and Arya are playing a game called Remainders. Pari chooses two positive integer x and k, and tells Arya k but not x. Arya have to find the value . There…