http://codeforces.com/contest/489 Problems     # Name     A SwapSort standard input/output 1 s, 256 MB    x2668 B BerSU Ball standard input/output 1 s, 256 MB    x2659 C Given Length and Sum of Digits... standard input/output 1 s, 256 MB    x2261 D U…

题目链接:http://codeforces.com/contest/489 A:SwapSort In this problem your goal is to sort an array consisting of n integers in at most n swaps. For the given array find the sequence of swaps that makes the array sorted in the non-descending order. Swaps…

http://codeforces.com/contest/489/problem/E E. Hiking time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output A traveler is planning a water hike along the river. He noted the suitable rest points…

http://codeforces.com/problemset/problem/489/D D. Unbearable Controversy of Being time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Tomash keeps wandering off and getting lost while he is wal…

http://codeforces.com/problemset/problem/489/C C. Given Length and Sum of Digits... time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have a positive integer m and a non-negative integer …

http://codeforces.com/problemset/problem/489/B B. BerSU Ball time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output The Berland State University is hosting a ballroom dance in celebration of its 1…

http://codeforces.com/problemset/problem/489/A A. SwapSort time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output In this problem your goal is to sort an array consisting of n integers in at most …

转载请注明出处: http://www.cnblogs.com/fraud/          ——by fraud A. SwapSort time limit per test    1 second memory limit per test      256 megabytes input      standard input output      standard output In this problem your goal is to sort an array consis…

题意:求该死的菱形数目.直接枚举两端的点.平均意义每一个点连接20条边,用邻接表暴力计算中间节点数目,那么中间节点任选两个与两端可组成的菱形数目有r*(r-1)/2. 代码: #include<iostream> #include<cstdio> #include<cmath> #include<map> #include<cstring> #include<algorithm> #define rep(i,a,b) for(int…

B. BerSU Ball time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output The Berland State University is hosting a ballroom dance in celebration of its 100500-th anniversary! n boys and m girls are al…

BerSU Ball time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output The Berland State University is hosting a ballroom dance in celebration of its 100500-th anniversary! n boys and m girls are alrea…

A. SwapSort time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output In this problem your goal is to sort an array consisting of n integers in at most n swaps. For the given array find the sequence…

C. Given Length and Sum of Digits... time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have a positive integer m and a non-negative integer s. Your task is to find the smallest and the la…

A. SwapSort time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output In this problem your goal is to sort an array consisting of n integers in at most n swaps. For the given array find the sequence…

这道题我临场想到了枚举菱形的起点和终点,然后每次枚举起点指向的点,每个指向的点再枚举它指向的点看有没有能到终点的,有一条就把起点到终点的路径个数加1,最后ans+=C(路径总数,2).每两个点都这么弄.但是我考虑时间复杂度n2前面的系数过大会超时,再想别的方法也没想出来.. 其实思路就是这样的,只不过时间上可以优化一下,就是用常用的两种做法不变而优化时间复杂度的方法:1.以空间换时间2.分步降维 #include <cstdio> #include <vector> using n…

B. BerSU Ball time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output The Berland State University is hosting a ballroom dance in celebration of its 100500-th anniversary! n boys and m girls are al…

C. Given Length and Sum of Digits... time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output You have a positive integer m and a non-negative integer s. Your task is to find the smallest and the la…

Codeforces Round #277 (Div. 2) A. Calculating Function time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output For a positive integer n let's define a function f: f(n) =  - 1 + 2 - 3 + .. + ( - 1)n…

题目传送门 /* 贪心+构造:因为是对称的,可以全都左一半考虑,过程很简单,但是能想到就很难了 */ /************************************************ Author :Running_Time Created Time :2015-8-3 9:14:02 File Name :B.cpp *************************************************/ #include <cstdio> #include &…

门户:Codeforces Round #277 (Div. 2) 486A. Calculating Function 裸公式= = #include <cstdio> #include <cstring> #include <algorithm> using namespace std ; typedef long long LL ; LL n ; int main () { while ( ~scanf ( "%I64d" , &n )…

Codeforces Round #504 (rated, Div. 1 + Div. 2, based on VK Cup 2018 Final) A. Single Wildcard Pattern Matching 题意就是匹配字符的题目,打比赛的时候没有看到只有一个" * ",然后就写挫了,被hack了,被hack的点就是判一下只有一个" * ". 代码: //A #include<iostream> #include<cstdio>…

Codeforces Round #405 (rated, Div. 2, based on VK Cup 2017 Round 1) 全场题解 菜鸡只会A+B+C,呈上题解: A. Bear and Big Brother 题意:我也没看太清,就是给你两个10以内的数a,b.a每天乘以3,b每天乘以2,求多少天后a大于b. 思路:应该是有公式的,不过看到数据这么小直接暴力乘求解.官方题解貌似就是这样,数据小就是水题. const int N=1e3+10; int main() { int a…

Codeforces Round #581(Div. 2) CF 1204 A. BowWow and the Timetable 题解:发现,$4$的幂次的二进制就是一个$1$后面跟偶数个$0$. 所以暴力判一下就好. Code: #include <bits/stdc++.h> #define N 110 using namespace std; char s[N]; int main() { scanf("%s", s + 1); int n = strlen(s +…

A. Is it rated? time limit per test:2 seconds memory limit per test:256 megabytes input:standard input output:standard output Is it rated? Here it is. The Ultimate Question of Competitive Programming, Codeforces, and Everything. And you are here to a…

Codeforces Round #432 (Div. 2, based on IndiaHacks Final Round 2017)  A. Arpa and a research in Mexican wave time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Arpa is researching the Mexican…

Codeforces Round #431 (Div. 2)  A. Odds and Ends time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Where do odds begin, and where do they end? Where does hope emerge, and will they ever break…

A. Is it rated? time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Is it rated? Here it is. The Ultimate Question of Competitive Programming, Codeforces, and Everything. And you are here to a…

题意: 思路: Codeforces Round #370(Solved: 4 out of 5) A - Memory and Crow 题意:有一个序列,然后对每一个进行ai = bi - bi + 1 + bi + 2 - bi + 3.... 的操作,最后得到了a 序列,给定 a 序列,求原序列. 思路:水. #include <set> #include <map> #include <stack> #include <queue> #includ…

地址:http://codeforces.com/contest/807/problem/D 题目: D. Dynamic Problem Scoring time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Vasya and Petya take part in a Codeforces round. The round las…

A. Uncowed Forces time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Kevin Sun has just finished competing in Codeforces Round #334! The round was 120 minutes long and featured five problems w…