思路:这题的关键就是重复根只可能是整数. 这样先求出所有的根的数目,在减去重复的根. 代码如下: #include <iostream> #include <cstring> #include <cstdio> #include <cmath> #define ll long long using namespace std; ]; int main(){ ll n,m; scanf("%I64d%I64d",&n,&m)…

Theatre Square time limit per test 2 seconds memory limit per test 64 megabytes input standard input output standard output Theatre Square in the capital city of Berland has a rectangular shape with the size n × m meters. On the occasion of the city'…

A permutation of length n is an array containing each integer from 1 to n exactly once. For example, q = [4, 5, 1, 2, 3] is a permutation. For the permutation q the square of permutation is the permutation p that p[i] = q[q[i]] for each i = 1... n. F…

A. Again Twenty Five! time limit per test 0.5 seconds memory limit per test 64 megabytes input standard input output standard output The HR manager was disappointed again. The last applicant failed the interview the same way as 24 previous ones. "Do…

N. Forecast time limit per test 0.5 seconds memory limit per test 64 megabytes input standard input output standard output The Department of economic development of IT City created a model of city development till year 2100. To prepare report about g…

Description The Department of economic development of IT City created a model of city development till year 2100. To prepare report about growth perspectives it is required to get growth estimates from the model. To get the growth estimates it is req…

N - Forecast Crawling in process... Crawling failed Time Limit:500MS     Memory Limit:65536KB     64bit IO Format:%I64d & %I64u Submit Status Description The Department of economic development of IT City created a model of city development till year…

UVA 1426 - Discrete Square Roots 题目链接 题意:给定X, N. R.要求r2≡x (mod n) (1 <= r < n)的全部解.R为一个已知解 思路: r2≡x (mod n)=>r2+k1n=x 已知一个r!,带入两式相减得 r2−r12=kn => (r+r1)(r−r1)=kn 枚举A,B,使得 A * B = n (r + r1)为A倍数 (r - r1)为B倍数 这样就能够推出 Aka−r1=Bkb+r1=r => Aka=Bk…

cf 460 E. Congruence Equation 数学题 题意: 给出一个x 计算<=x的满足下列的条件正整数n的个数 \(p是素数,2 ≤ p ≤ 10^{6} + 3, 1 ≤ a, b < p, 1 ≤ x ≤ 10^{12}\) 思路: 题目中存在两个循环节 \(n % p\) 和 \(a ^ n % p\), 循环节分别为\(p,p-1\) 我们枚举\(i = n\ (mod)\ (p - 1)\) 可以得到两个方程 \[ n\ \equiv\ i\ mod\ (p-1)…

Loops are often used in programs that compute numerical results by starting with an approximate answer and iteratively improving it. For example, one way of computing square roots is Newton’s method. Suppose that you want to know the square root of a…