[POJ2891]Strange Way to Express Integers(拓展CRT) 题面 Vjudge 板子题. 题解 拓展\(CRT\)模板题. #include<iostream> #include<cstdio> using namespace std; #define ll long long #define MAX 111111 ll exgcd(ll a,ll b,ll &x,ll &y) { if(!b){x=1,y=0;return a;…

http://poj.org/problem?id=2891 (题目链接) 题意 求解线性同余方程组,不保证模数一定两两互质. Solotion 一般模线性方程组的求解,详情请见:中国剩余定理 细节 注意当最后发现方程无解直接退出时,会导致有数据没有读完,然后就会Re,所以先用数组将所有数据存下来. 代码 // poj2891 #include<algorithm> #include<iostream> #include<cstdlib> #include<cst…

题意: 给出n个模方程x=a(mod r) 求x的最小解 题解: 这就是个线性模方程组的模版题- - 但是有一些要注意的地方 extgcd算出来的解x可能负数  要让x=(x%mo+mo)%mo 而且mo不是等于lcm(r1,r2) 而是r2/gcd(r1,r2) 代码: #include <cstdio> typedef long long ll; ll n,a,r; ll extgcd(ll &x,ll &y,ll a,ll b){ if (!b){ x=,y=; retu…

中国剩余定理/扩展欧几里得 题目大意:求一般模线性方程组的解(不满足模数两两互质) solution:对于两个方程 \[ \begin{cases} m \equiv r_1 \pmod {a_1} \\ m \equiv r_2 \pmod{a_2} \end{cases} \] 我们可以列出式子 $$ a_1x+r_1=a_2y+r_2 $$ 利用扩展欧几里得解出一个可行解$M'$.那么我们就可以将两个限制条件合为一个: $$ m \equiv M' \pmod{ lcm(a_1,a_2)}…

1635:[例 5]Strange Way to Express Integers sol:貌似就是曹冲养猪的加强版,初看感觉非常没有思路,经过一番艰辛的***,得到以下的结果 随便解释下给以后的自己听:K是要求的数字 第一个读入的A1,Mod1不用改,从2开始做,把Mod2改成LCM,A2改成Ans,接着搞3 /* 原式: X = A[1] (%Mod[1]) X = A[2] (%Mod[2]) ... X = A[n] (%Mod[n]) K[1]*Mod[1]+A[1] = X K[2]…

Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is described as following: Choose k different positive integers a1, a2, -, ak. For some non-negative m, divide it by ev…

[题目链接] http://poj.org/problem?id=2891 [算法] exgcd [代码] #include <algorithm> #include <bitset> #include <cctype> #include <cerrno> #include <clocale> #include <cmath> #include <complex> #include <cstdio> #incl…

题目链接 [VJ传送门] 题目描述 给你\(a_1...a_n\)和\(m_1...m_n\),求一个最小的正整数\(x\),满足\(\forall i\in[1,n] \equiv a_i(mod \ mi)\). 分析 很显然,中国剩余定理无法解决\(m_i\)之间非互质的问题. 需要用\(exCRT\). 假设\(x\)是前\(k-1\)个方程推出来的答案,那么第一个方程可以直接得出自己的答案就是\(a_1\). 设\(M=lcm(m_1,m_2...m_{k-1})\),那么显然得到\(…

#include<bits/stdc++.h> #define ll long long using namespace std; ll n,m,a,lcm,now; bool flag; void exgcd(ll a,ll b,ll &d,ll &x,ll &y) { ) { d=a; x=; y=; } else { exgcd(b,a%b,d,x,y); ll t=x; x=y; y=t-a/b*y; } } int main() { ll d,x,y,k; w…

题意:Elina看一本刘汝佳的书(O_O*),里面介绍了一种奇怪的方法表示一个非负整数 m .也就是有 k 对 ( ai , ri ) 可以这样表示--m%ai=ri.问 m 的最小值. 解法:拓展欧几里德求解同余方程组的最小非负整数解.(感觉挺不容易的......+_+@) 先看前2个关系式:                       m%a1=r1 和 m%a2=r2 →                                                           …

写一下自己的理解,下面附上转载的:若a==b(modk);//这里的==指的是同余,我用=表示相等(a%k=b)a-b=kt(t为整数)以前理解的错误思想:以前认为上面的形式+(a-tb=k)也是成立的,今天一想随便就能举出一个反例11==5(mod3)同样是求这个东西..X mod m1=r1X mod m2=r2.........X mod mn=rn 首先,我们看两个式子的情况X mod m1=r1……………………………………………………………(1)X mod m2=r2…………………………

http://poj.org/problem?id=2891 题目大意: k个不同的正整数a1,a2,...,ak.对于一些非负m,满足除以每个ai(1≤i≤k)得到余数ri.求出最小的m. 输入和输出中的所有整数都是非负数,可以用64位整数类型表示. —————————————— 首先我们打眼一看可能是孙子定理. 但是我们无法保证a一定互质. 那么显然就要用我们的可爱的exgcd啦! (下面题解根据这位大佬所懂http://blog.csdn.net/zmh964685331/article/…

Strange Way to Express Integers DescriptionElina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is described as following:Choose k different positive integers a1, a2, …, ak. For some n…

0.引子 每一个讲中国剩余定理的人,都会从孙子的一道例题讲起 有物不知其数,三三数之剩二,五五数之剩三,七七数之剩二.问物几何? 1.中国剩余定理 引子里的例题实际上是求一个最小的x满足 关键是,其中r1,r2,--,rk互质 这种问题都有多解,每一个解都为最小的解加上若干个lcm(r1,r2,...,rk),这个不用我证了吧(-_-||) 解决这个问题的方法是构造法, 先构造k个数 满足, 这样就保证 ,但是由于 bi 乘了除 ri 以外所有 r,所以bi模其它的 r 都为 0, 再把所有 b…

题意 Language:Default Strange Way to Express Integers Time Limit: 1000MS Memory Limit: 131072K Total Submissions: 21651 Accepted: 7266 Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative inte…

同余方程组 例题1:pku2891Strange Way to Express Integers 中国剩余定理求的同余方程组mod 的数是两两互素的.然而本题(一般情况,也包括两两互素的情况,所以中国剩余定理成为了“时代的眼泪”)mod的数可能不是互素,所以要转换一下再求. P=b1(mod a1);  P / a1 ==?~~~~b1 P =b2(mod a2); P =b3(mod a3); …… P =bn(mod an); a1~an,b1~bn是给出来的. 解: 第一条:a1*x+b1…

上周写了一个node+experss的爬虫小入门.今天继续来学习一下,写一个爬虫2.0版本. 这次我们不再爬博客园了,咋玩点新的,爬爬电影天堂.因为每个周末都会在电影天堂下载一部电影来看看. talk is cheap,show me the code! [原]小玩node+express爬虫-1:http://www.cnblogs.com/xianyulaodi/p/6049237.html 抓取页面分析 我们的目标: 1.抓取电影天堂首页,获取左侧最新电影的169条链接 2.抓取169部新…

Strange Way to Express Integers Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 9472   Accepted: 2873 Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is…

Strange Way to Express Integers Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 10907   Accepted: 3336 Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is…

F - Strange Way to Express Integers Time Limit:1000MS     Memory Limit:131072KB     64bit IO Format:%I64d & %I64u Submit Status Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers.…

Strange Way to Express Integers Time Limit:1000MS Memory Limit:131072KB 64bit IO Format:%I64d & %I64u Submit Status Practice POJ 2891   Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative i…

http://poj.org/problem?id=2891 Strange Way to Express Integers Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 11970   Accepted: 3788 Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express no…

Strange Way to Express Integers Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 8193   Accepted: 2448 Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is…

Strange Way to Express Integers Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 16839   Accepted: 5625 Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is…

I. Strange Way to Express Integers 题目描述 原题来自:POJ 2891 给定 2n2n2n 个正整数 a1,a2,⋯,ana_1,a_2,\cdots ,a_na​1​​,a​2​​,⋯,a​n​​ 和 m1,m2,⋯,mnm_1,m_2,\cdots ,m_nm​1​​,m​2​​,⋯,m​n​​,求一个最小的正整数 xxx,满足 ∀i∈[1,n],x≡ai (modmi ),或者给出无解. 输入格式 多组数据. 每组数据第一行一个整数 nnn:接下来 nn…

P4777 [模板]扩展中国剩余定理(EXCRT) excrt模板 我们知道,crt无法处理模数不两两互质的情况 然鹅excrt可以 设当前解到第 i 个方程 设$M=\prod_{j=1}^{i-1}b[j]$ ,$ res$是前$ i-1 $个方程的最小解 则$ res+x*M$ 是前 $i-1 $个方程的通解 那么我们求的就是 $res+x*M ≡ a[i] (mod b[i])$ $<=> x*M - y*b[i] = a[i]-res$ 用exgcd求出的解为 t (当且仅当 gcd…

Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is described as following: Choose k different positive integers a1, a2, …, ak. For some non-negative m, divide it by ev…

Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 8476   Accepted: 2554 Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is described as following: Choose k…

http://poj.org/problem?id=2891 Time Limit: 1000MS   Memory Limit: 131072K Total Submissions: 16849   Accepted: 5630 Description Elina is reading a book written by Rujia Liu, which introduces a strange way to express non-negative integers. The way is…

Time Limit: 5000MS   Memory Limit: 131072K Total Submissions: 97008   Accepted: 30285 Case Time Limit: 2000MS Description You have N integers, A1, A2, ... , AN. You need to deal with two kinds of operations. One type of operation is to add some given…