B. Fedya and Maths time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Fedya studies in a gymnasium. Fedya's maths hometask is to calculate the following expression: (1n + 2n + 3n + 4n) mod 5 f…

题目传送门 /* 题意:选择a[k]然后a[k]-1和a[k]+1的全部删除,得到点数a[k],问最大点数 DP:状态转移方程:dp[i] = max (dp[i-1], dp[i-2] + (ll) i * cnt[i]); 只和x-1,x-2有关,和顺序无关,x-1不取,x-2取那么累加相同的值,ans = dp[mx] */ #include <cstdio> #include <algorithm> #include <cstring> #include <…

题目传送门 /* DP:从1到最大值,dp[i][1/0] 选或不选,递推更新最大值 */ #include <cstdio> #include <algorithm> #include <cmath> #include <cstring> using namespace std; typedef long long ll; ; const int INF = 0x3f3f3f3f; ll dp[MAXN][]; ll cnt[MAXN]; ll work(…

http://codeforces.com/contest/456/problem/A A. Laptops time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output One day Dima and Alex had an argument about the price and quality of laptops. Dima thi…

A. Laptops 题目意思: 给定n台电脑,第i台电脑的价格是ai ,质量是bi ,问是否存在一台电脑价格比某台电脑价格底,但质量确比某台电脑的质量高,即是否存在ai < aj 且 bi > bj ? 解题思路: 这题一定要看题目,a都是1~n的不同数,b也是1~n的不同数,此题只需要判断ai 是否等于bi ,如果ai != bi 的话,则输出“Happy Alex”,如果所有的ai  == bi 则输出“Poor Alex” 证明:先将a按照从小到大排序,当i<j时ai <…

Description Fedya studies in a gymnasium. Fedya's maths hometask is to calculate the following expression: (1n + 2n + 3n + 4n) mod 5 for given value of n. Fedya managed to complete the task. Can you? Note that given number n can be extremely large (e…

A. Laptops time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output One day Dima and Alex had an argument about the price and quality of laptops. Dima thinks that the more expensive a laptop is, the…

题目链接 A. Laptops time limit per test:1 secondmemory limit per test:256 megabytesinput:standard inputoutput:standard output One day Dima and Alex had an argument about the price and quality of laptops. Dima thinks that the more expensive a laptop is, t…

A. Laptops time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output One day Dima and Alex had an argument about the price and quality of laptops. Dima thinks that the more expensive a laptop is, the…

D. Serega and Fun Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/455/problem/D Description Serega loves fun. However, everyone has fun in the unique manner. Serega has fun by solving query problems. One day Fedor came up w…