博学善思

摘要： Building and maintaining roads among communities in the far North is an expensive business. With this in mind, the roads are build such that there is 阅读全文

摘要： 一个A和两个B一共可以组成三种字符串:"ABB","BAB","BBA". 给定若干字母和它们相应的个数,计算一共可以组成多少个不同的字符串. Input每组测试数据分两行,第一行为n(1<=n<=26),表示不同字母的个数,第二行为n个数A1,A2,...,An(1<=Ai<=12),表示每种字母 阅读全文

摘要： 五一到了，PKU-ACM队组织大家去登山观光，队员们发现山上一个有N个景点，并且决定按照顺序来浏览这些景点，即每次所浏览景点的编号都要大于前一个浏览景点的编号。同时队员们还有另一个登山习惯，就是不连续浏览海拔相同的两个景点，并且一旦开始下山，就不再向上走了。队员们希望在满足上面条件的同时，尽可能多的 阅读全文

摘要： Given two integers, a and b, you should check whether a is divisible by b or not. We know that an integer a is divisible by an integer b if and only i 阅读全文

摘要： In the year 2008, the 29th Olympic Games will be held in Beijing. This will signify the prosperity of China and Beijing Olympics is to be a festival f 阅读全文

摘要： You are playing a two player game. Initially there are n integer numbers in an array and player A and B get chance to take them alternatively. Each pl 阅读全文

摘要： Diophantus of Alexandria was an Egypt mathematician living in Alexandria. He was one of the first mathematicians to study equations where variables we 阅读全文

摘要： You've got a string s = s1s2... s|s| of length |s|, consisting of lowercase English letters. There also are q queries, each query is described by two 阅读全文

摘要： Problem Description One day, Y_UME got an integer N and an interesting program which is shown below:Y_UME wants to play with this program. Firstly, he 阅读全文

摘要： 题目描述 求关于xx的同余方程 a x \equiv 1 \pmod {b}ax≡1(modb) 的最小正整数解。 输入输出格式 输入格式： 一行，包含两个正整数 a,ba,b，用一个空格隔开。 输出格式： 一个正整数 x_0x0​，即最小正整数解。输入数据保证一定有解。 输入输出样例 输入样例#1 阅读全文