Magic Pairs Problem's Link Mean: 已知N.A0.B0,对于给定X.Y,若A0X+B0Y能被N整除,则AX+BY也能被N整除,求所有的A.B.(0<=A.B<N) analyse: 这道题目就是先把A0和B0和N都除以他们的最大公约数,然后就是枚举A0和B0的0到N-1倍. 最后快排,注意一下有0的情况. Time complexity: O(N) view code /** * ------------------------------------------…

题意: 对于给出的一个整数N,和一对(A0,B0) 找到所有的整数对(A,B)满足 : 对于任意 X,Y 当 A0 * X + B0 * Y 能被 N 整除时 A * X + B * Y 也能被 N 整除 Solution:               如果AX+BY能被N整除,则dAX+dBY也能,因A,B<N,所以(dA mod N)X+(dB mod N)Y也能,把所有情况枚举完排序输出 参考代码:              #include <stdio.h> #include…

119. Magic Pairs time limit per test: 0.5 sec. memory limit per test: 4096 KB “Prove that for any integer X and Y if 5X+4Y is divided by 23 than 3X+7Y is divided by 23 too.” The task is from city Olympiad in mathematics in Saratov, Russia for schoolc…

题目大意:如果A0*X + B0*Y能够整除 N,求出来多有少A*X+B*Y 也能够整除去N,求出所有的A,B(0<=A,B<N) 分析:有条件可以知道 A*X+B*Y = K *(A0*X + B0*Y)% N ====> (K * A0) % N = A, (K * B0) % N = B, (k=[0....N)). ps.记得排序去重复...... 代码如下: ============================================================…

http://acm.sgu.ru/problemset.php?contest=0&volume=1 101 Domino 欧拉路 102 Coprime 枚举/数学方法 103 Traffic Lights 最短路 104 Little Shop of Flowers 动态规划 105 Div 3 找规律 106 The Equation 扩展欧几里德 107 987654321 Problem 找规律 108 Self-numbers II 枚举+筛法递推 109 Magic of Dav…

Pairs Forming LCM (LightOJ - 1236)[简单数论][质因数分解][算术基本定理](未完成) 标签: 入门讲座题解 数论 题目描述 Find the result of the following code: long long pairsFormLCM( int n ) { long long res = 0; for( int i = 1; i <= n; i++ ) for( int j = i; j <= n; j++ ) if( lcm(i, j) ==…

In the secret book of ACM, it’s said: “Glory for those who write short ICPC problems. May they live long, and never get Wrong Answers” . Everyone likes problems with short statements. Right? Let’s have five positive numbers: X1,X2,X3,X4,X5. We can fo…

题目链接 题目描述 Eddy has solved lots of problem involving calculating the number of coprime pairs within some range. This problem can be solved with inclusion-exclusion method. Eddy has implemented it lots of times. Someday, when he encounters another copr…

B. Ralph And His Magic Field time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Ralph has a magic field which is divided into n × m blocks. That is to say, there are n rows and m columns on th…

Do you think that magic is simple? That some hand-waving and muttering incomprehensible blubber is enough to conjure wonderful gardens or a fireball to burn your enemies to ashes? The reality is a little more complicated than that. To master skills,…