D. Memory and Scores   Memory and his friend Lexa are competing to get higher score in one popular computer game. Memory starts with score a and Lexa starts with score b. In a single turn, both Memory and Lexa get some integer in the range [ - k;k] (…

D. Memory and Scores 题目连接: http://codeforces.com/contest/712/problem/D Description Memory and his friend Lexa are competing to get higher score in one popular computer game. Memory starts with score a and Lexa starts with score b. In a single turn, b…

E. Memory and Casinos 题目连接: http://codeforces.com/contest/712/problem/E Description There are n casinos lined in a row. If Memory plays at casino i, he has probability pi to win and move to the casino on the right (i + 1) or exit the row (if i = n),…

地址:http://codeforces.com/problemset/problem/712/C 题目: C. Memory and De-Evolution time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Memory is now interested in the de-evolution of objects, sp…

地址:http://codeforces.com/problemset/problem/712/B 题目: B. Memory and Trident time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Memory is performing a walk on the two-dimensional plane, starti…

C. Memory and De-Evolution 题目连接: http://codeforces.com/contest/712/problem/C Description Memory is now interested in the de-evolution of objects, specifically triangles. He starts with an equilateral triangle of side length x, and he wishes to perfor…

B. Memory and Trident 题目连接: http://codeforces.com/contest/712/problem/B Description Memory is performing a walk on the two-dimensional plane, starting at the origin. He is given a string s with his directions for motion: An 'L' indicates he should mo…

A. Memory and Crow 题目连接: http://codeforces.com/contest/712/problem/A Description There are n integers b1, b2, ..., bn written in a row. For all i from 1 to n, values ai are defined by the crows performing the following procedure: The crow sets ai ini…

题目链接: http://codeforces.com/contest/712/problem/E 题目大意: 一条直线上有n格,在第i格有pi的可能性向右走一格,1-pi的可能性向左走一格,有2中操作:单点修改pi以及询问从L格出发最终从R格离开区间[L,R]的概率. 这题在cf上A的人比较少,本来不打算去做的,然后看了下是概率的题目,比较感兴趣,就去做了下,然后发现并不会做,就搜了题解. 题解: 参考http://www.cnblogs.com/qscqesze/p/5868047.html…

Hard problem 题目链接: http://codeforces.com/contest/706/problem/C Description Vasiliy is fond of solving different tasks. Today he found one he wasn't able to solve himself, so he asks you to help. Vasiliy is given n strings consisting of lowercase Engl…

C. Memory and De-Evolution time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output Memory is now interested in the de-evolution of objects, specifically triangles. He starts with an equilateral tr…

Description Memory is now interested in the de-evolution of objects, specifically triangles. He starts with an equilateral triangle of side length x, and he wishes to perform operations to obtain an equilateral triangle of side length y. In a single…

Description Memory is performing a walk on the two-dimensional plane, starting at the origin. He is given a string s with his directions for motion: An 'L' indicates he should move one unit left. An 'R' indicates he should move one unit right. A 'U'…

Description There are n integers b1, b2, ..., bn written in a row. For all i from 1 to n, values ai are defined by the crows performing the following procedure: The crow sets ai initially 0. The crow then adds bi to ai, subtracts bi + 1, adds the bi …

A. Memory and Crow time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output There are n integers b1, b2, ..., bn written in a row. For all i from 1 to n, values ai are defined by the crows performi…

A. Memory and Crow time limit per test 2 seconds memory limit per test 256 megabytes input standard input output standard output There are n integers b1, b2, ..., bn written in a row. For all i from 1 to n, values ai are defined by the crows performi…

A B C :=w= D:两个人得分互不影响很关键 一种是f[i][j]表示前i轮,分差为j的方案数 明显有f[i][j]=f[i-1][j-2k]+2*f[i-1][j-2k+1]+...+(2k+1)f[i-1][j]+... 枚举是K*T*T,转移是K 超时 不过发现转移的时候可以理解为j是j-1的算式的整个区间移动,于是可以维护f[i-1]的前缀和来达到O(1)的转移 另一种f[i][j]表示前i轮,某个人分数为j的方案数(两人互不影响,无先后手之分,所以两人等价) 式子写出来就少了第一…

题目链接: http://codeforces.com/problemset/problem/268/E E. Playlist time limit per test 1 secondmemory limit per test 256 megabytes 问题描述 Manao's friends often send him new songs. He never listens to them right away. Instead, he compiles them into a play…

题目链接: http://codeforces.com/contest/464/problem/C J. Substitutes in Number time limit per test 1 secondmemory limit per test 256 megabytes 问题描述 Andrew and Eugene are playing a game. Initially, Andrew has string s, consisting of digits. Eugene sends A…

B. Maximum Submatrix 2 Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/problemset/problem/375/B Description You are given a matrix consisting of digits zero and one, its size is n × m. You are allowed to rearrange its rows. What is…

B. Strip Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/487/problem/B Description Alexandra has a paper strip with n numbers on it. Let's call them ai from left to right. Now Alexandra wants to split it into some pieces (p…

E. LIS of Sequence Time Limit: 20 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/486/problem/E Description The next "Data Structures and Algorithms" lesson will be about Longest Increasing Subsequence (LIS for short) of a sequence.…

D. Duff in Beach Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/588/problem/D Description While Duff was resting in the beach, she accidentally found a strange array b0, b1, ..., bl - 1 consisting of l positive integers. Th…

B. Modulo Sum Time Limit: 1 Sec Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/577/problem/B Description You are given a sequence of numbers a1, a2, ..., an, and a number m. Check if it is possible to choose a non-empty subsequence aij such…

题目链接: http://codeforces.com/problemset/problem/149/D D. Coloring Brackets time limit per test2 secondsmemory limit per test256 megabytes 问题描述 Once Petya read a problem about a bracket sequence. He gave it much thought but didn't find a solution. Toda…

题目链接: http://www.codeforces.com/contest/476/problem/E E. Dreamoon and Strings time limit per test 1 secondmemory limit per test 256 megabytes 问题描述 Dreamoon has a string s and a pattern string p. He first removes exactly x characters from s obtaining…

C. Writing Code Time Limit: 20 Sec  Memory Limit: 256 MB 题目连接 http://codeforces.com/contest/544/problem/C Description Programmers working on a large project have just received a task to write exactly m lines of code. There are n programmers working o…

题目链接:http://codeforces.com/contest/294/problem/B B. Shaass and Bookshelf time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Shaass has n books. He wants to make a bookshelf for all his books.…

题目链接:http://codeforces.com/problemset/problem/812/B B. Sagheer, the Hausmeister time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Some people leave the lights at their workplaces on when they…

题目链接:http://codeforces.com/problemset/problem/455/A A. Boredom time limit per test 1 second memory limit per test 256 megabytes input standard input output standard output Alex doesn't like boredom. That's why whenever he gets bored, he comes up with…