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Little Mishka enjoys programming. Since her birthday has just passed, her friends decided to present her with array of non-negative integers a1, a2, …, an of n elements!Mishka loved the array and she i

You are given a rooted tree of N nodes, labeled from 1 to N. To the ith node a non-negative value ai is assigned.An ordered pair of nodes (u,v) is said to be weak if (1) u is an ancestor of v (Note

Given some segments which are paralleled to the coordinate axis. You need to count the number of their intersection. The input data guarantee that no two segments share the same endpoint, no covered se

Given a sequence A with length n,count how many quadruple (a,b,c,d) satisfies: a≠b≠c≠d,1≤a<b≤n,1≤c<d≤n,Aa<Ab,Ac>Ad,a≠b≠c≠d,1≤a<b≤n,1≤c<d≤n,Aa<Ab,Ac>Ada≠b≠c≠d,1≤a<b≤n,1≤c<d≤n,A_a<A_b,A_c>A_d,a≠b≠c≠d,1≤a

题目链接 题目大意，在一串无穷的1，2，3…n的串值，有k次操作，每次操作给出两个数a，b，即把坐标a和坐标b的值交换，问最后有多少个逆序对，0<=k<=105,a和b在int范围内0<=k<=10^5,a和b在int范围内 分析：问题的关键是，操作次数相对与整个序列是比较稀疏的，也就是说会有许多连续的数串 ，我们就是把这些连续的数串缩微一个点，而点的权值即为这个数串的数量，用离散化来处理，最后

You have N integers, A1, A2, … , AN. You need to deal with two kinds of operations. One type of operation is to add some given number to each number in a given interval. The other is to ask for the su...

N (2 &lt;= N &lt;= 8,000) cows have unique brands in the range 1..N. In a spectacular display of poor judgment, they visited the neighborhood ‘watering hole’ and drank a few too many beers before dinn...

Data structure is one of the basic skills for Computer Science students, which is a particular way of storing and organizing data in a computer so that it can be used efficiently. Today let me introdu...

Given a sequence of integers a 1 , a 2 , …, a n and q pairs of integers (l 1 , r 1 ), (l 2 , r 2 ), …, (l q , r q ), find count(l 1 , r 1 ), count(l 2 , r 2 ), …, count(l q , r q ) where count(i, j) ...