C. Balance 题目链接 http://codeforces.com/contest/17/problem/C 题面 Nick likes strings very much, he likes to rotate them, sort them, rearrange characters within a string... Once he wrote a random string of characters a, b, c on a piece of paper and began…

C. Balance time limit per test 3 seconds memory limit per test 128 megabytes input standard input output standard output Nick likes strings very much, he likes to rotate them, sort them, rearrange characters within a string... Once he wrote a random…

Codeforces Beta Round #17 题目链接:点击我打开题目链接 大概题意: 给你 \(b\),\(n\),\(c\). 让你求:\((b)^{n-1}*(b-1)\%c\). \(2<=b<=10^{10^6},1<=n<=10^{10^6},1<=c<=10^9\) 简明题解: 因为 \(b\) , \(n\)都太大了.关键是求 \((b)^{n-1}\%c\) 所以,我们可以利用欧拉函数 \(phi()\) 的性质. 对于\(a^{b} \% c\…

Codeforces Beta Round #16 (Div. 2 Only) E. Fish 题目链接:## 点击打开链接 题意: 有 \(n\) 条鱼,每两条鱼相遇都会有其中一只吃掉对方,现在给你一个 \(n * n\)的矩阵,表示 \(i\) 吃掉 \(j\) 的概率,最后问你每条鱼存活的概率. 题解: 最多有 \(18\) 条鱼,吃掉的概率都不一样,可以用状态压缩,设\(dp[1<<n]\)种状态,最多有 \(1<<18\) 种状态. $ dp[i]$ 表示当前鱼的状态为…

A - Noldbach problem 题面链接 http://codeforces.com/contest/17/problem/A 题面 Nick is interested in prime numbers. Once he read about Goldbach problem. It states that every even integer greater than 2 can be expressed as the sum of two primes. That got Nic…

A. Noldbach problem Nick is interested in prime numbers. Once he read about Goldbach problem. It states that every even integer greater than 2 can be expressed as the sum of two primes. That got Nick's attention and he decided to invent a problem of…

D. Notepad time limit per test 2 seconds memory limit per test 64 megabytes input standard input output standard output Nick is attracted by everything unconventional. He doesn't like decimal number system any more, and he decided to study other numb…

D. Beautiful numbers Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/55/problem/D Description Volodya is an odd boy and his taste is strange as well. It seems to him that a positive integer number is beautiful if and only i…

题目大意 给一个数列,长度不超过 5000,每次可以将其中的一个数加 1 或者减 1,问,最少需要多少次操作,才能使得这个数列单调不降 数列中每个数为 -109-109 中的一个数 做法分析 先这样考虑:如果操作的次数最少,那么最终得到的不降的数列,必然是由原始数列中的数组成的,具体的证明可以使用反证法 知道了上面讲述的性质,这题就好搞了 先将原始数列(设为 A,共 n 个数)中所有的数去重并从小到达排序,保存在另一个数列中(设为 B,共 m 个数) 定义状态:f[i][j] 表示将原始数列中的…

Codeforces Beta Round #72 (Div. 2 Only) http://codeforces.com/contest/84 A #include<bits/stdc++.h> using namespace std; #define lson l,mid,rt<<1 #define rson mid+1,r,rt<<1|1 #define sqr(x) ((x)*(x)) #define pb push_back #define eb emplac…