随笔分类 - OJ---HDU
摘要：题意：给定A，B长度相同的字符串，Q次操作，修改操作位单个字符修改，查询操作为询问从某点开始有多少连续相同的字符。 思路：我们把不相同的设为1，相同的设为0，那么询问就是找下一个为1的为位置，可以用线段树解决，可以用set的lower_bound解决，这里用bitset的Find_next函数，效率
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摘要：题意：给定N个组合，每个组合有a和b，现在求最长序列，满足a不升，b不降。 思路：三位偏序，CDQ分治。 但是没想到怎么输出最小字典序，我好菜啊。 最小字典序： 我们倒序CDQ分治，ans[i]表示倒序的以i为结尾的最长序列，如果当前的ans[i]==目前最大，而且满足序列要求，就输出。
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摘要：Given you a sequence of number a 1, a 2, ..., a n, which is a permutation of 1...n. You need to answer some queries, each with the following format: G
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摘要：In graph theory, the complement of a graph G is a graph H on the same vertices such that two distinct vertices of H are adjacent if and only if they a
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摘要：Jimmy experiences a lot of stress at work these days, especially since his accident made working difficult. To relax after a hard day, he likes to wal
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摘要：The math department has been having problems lately. Due to immense amount of unsolicited automated programs which were crawling across their pages, t
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摘要：题意：T组数据，给次给出N，M，K，多少种方案，用[0,N-1]范围的数，表示一个M排列，其和为K； 思路：隔板法，不限制[0,N-1]的时候答案是C(M+K-1,M-1)；那么我们减去至少一个>=N，加上至少两个>=N....即可得到答案。 假设至少一个隔板里的数大于大于N，我们从这个隔板里抽出N
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摘要：一个包含四个点的完全图，可以在任意节点出发，可以在任意节点结束，给出每个点被经过的次数，求有多少种合法的遍历序列。如果两个序列至少有一位是不同的，则认为它们不相同。 Input Sample Output 题意：给a个A，b个B，c个C，d个D，求有少种排列，使得相邻的两个不同。 思路：用容斥来做，
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摘要：There is a connected undirected graph with weights on its edges. It is guaranteed that each edge appears in at most one simple cycle. Assuming that th
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摘要：Declare: k=∑ m i=1 φ(i∗n) mod 1000000007 k=∑i=1mφ(i∗n) mod 1000000007 n n is a square-free number. φ φ is the Euler's totient function. find: ans=k k
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摘要：There are n n apples on a tree, numbered from 1 1 to n n . Count the number of ways to pick at most m m apples. InputThe first line of the input conta
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摘要：Yellowstar likes integers so much that he listed all positive integers in ascending order,but he hates those numbers which can be written as a^b (a, b
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摘要：Tom owns a company and he is the boss. There are n staffs which are numbered from 1 to n in this company, and every staff has a ability. Now, Tom is g
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摘要：题面太丑了，就不复制了。 题意：F1=A； F2=B； Fn=D*Fn-1+C*Fn-2+P/i；求Fn。 思路：根据P/i的值划分区间，每个区间矩阵求。 带常数的矩阵：
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摘要：There are n numbers 3^0, 3^1, . . . , 3^n-1. Each time you can choose a subset of them (may be empty), and then add them up. Count how many numbers ca
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摘要：Senior Pan fails in his discrete math exam again. So he asks Master ZKC to give him graph theory problems everyday. The task is simple : ZKC will give
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摘要：There is a tree having N vertices. In the tree there are K monkeys (K <= N). A vertex can be occupied by at most one monkey. They want to remove some
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摘要：Do you like painting? Little D doesn't like painting, especially messy color paintings. Now Little B is painting. To prevent him from drawing messy pa
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摘要：Bob's school has a big playground, boys and girls always play games here after school. To protect boys and girls from getting hurt when playing happil
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