Clockwise Time Limit: 1000ms   Memory limit: 65536K  有疑问?点这里^_^ 题目描述 Saya have a long necklace with N beads, and she signs the beads from 1 to N. Then she fixes them to the wall to show N-1 vectors – vector i starts from bead i and end up with bead i…

Ivan comes again! Time Limit: 1000ms   Memory limit: 65536K  有疑问?点这里^_^ 题目描述 The Fairy Ivan gave Saya three problems to solve (Problem F). After Saya finished the first problem (Problem H), here comes the second.This is the enhanced version of Proble…

Balloons Time Limit: 1000MS Memory limit: 65536K 题目描述 Both Saya and Kudo like balloons. One day, they heard that in the central park, there will be thousands of people fly balloons to pattern a big image.They were very interested about this event, an…

Shopping Time Limit: 1000MS Memory limit: 65536K 题目描述 Saya and Kudo go shopping together.You can assume the street as a straight line, while the shops are some points on the line.They park their car at the leftmost shop, visit all the shops from left…

Hello World! Time Limit: 1000MS Memory limit: 65536K 题目描述 We know that Ivan gives Saya three problems to solve (Problem F), and this is the first problem.“We need a programmer to help us for some projects. If you show us that you or one of your frien…

The Android University ACM Team Selection Contest Time Limit: 1000ms   Memory limit: 65536K  有疑问?点这里^_^ 题目描述  Now it's 20000 A.D., and the androids also participate in the ACM Inter-national Collegiate Programming Contest (ACM/ICPC). In order to sele…

Identifiers Time Limit: 1000ms   Memory limit: 65536K  有疑问?点这里^_^ 题目描述  Identifier is an important concept in the C programming language. Identifiers provide names for several language elements, such as functions, variables, labels, etc. An identifie…

Crack Mathmen Time Limit: 1000ms   Memory limit: 65536K  有疑问?点这里^_^ 题目描述  Since mathmen take security very seriously, they communicate in encrypted messages. They cipher their texts in this way: for every characther c in the message, they replace c w…

题目链接: http://acm.nyist.edu.cn/JudgeOnline/problem.php?pid=1255 描述 Given N (4 <= N <= 100)  rectangles and the lengths of their sides ( integers in the range 1..1,000), write a program that finds the maximum K for which there is a sequence of K of th…

题目大意: n个点,第i个点和第i+1个点可以构成向量,问最少删除多少个点可以让构成的向量顺时针旋转或者逆时针旋转. 分析: dp很好想,dp[j][i]表示以向量ji(第j个点到第i个点构成的向量)为终点的最大顺时针/逆时针向量数.状态转移方程为 dp[j][i] = max{dp[k][j]+1}. 问题个关键是如何判断2个向量是顺时针还是逆时针. 计算几何用的知识是求叉积和点积,叉积的作用是判断两个向量的左右(顺逆),点积的作用是判断两个向量的前后.举个例子,假设有2个向量v1,v2,‘*…