Cao Cao made up a big army and was going to invade the whole South China. Yu Zhou was worried about it. He thought the only way to beat Cao Cao is to have a spy in Cao Cao's army. But all generals and soldiers of Cao Cao were loyal, it's impossible t…

The Battle of Chibi Cao Cao made up a big army and was going to invade the whole South China. Yu Zhou was worried about it. He thought the only way to beat Cao Cao is to have a spy in Cao Cao's army. But all generals and soldiers of Cao Cao were loya…

对于求逆序数问题,学会去利用树状数组进行转换求解方式,是很必要的. 一般来说我们求解逆序数,是在给定一串序列里,用循环的方式找到每一个数之前有多少个比它大的数,算法的时间复杂度为o(n2). 那么我们通过树状数组可以明显提高时间效率. 我们可以按照排列的顺序依次将数字放入树状数组中,并依次更新预与之相关联的树状数组元素.那么在将其更新完毕后,我们知道每个数对应的树状数组元素的左边的数肯定比它小,我们在以序列顺序依次更新树状数组时,如果有值在它前面出现,那么它对应的树状数组元素(在这个题目里存放的…

题目大意: 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>Ada≠b≠c≠d,1≤a<b≤n,1≤c<d≤n,Aa<Ab,Ac>Ad. A1,A2⋯AnA1,A2⋯An.  1≤n≤500001≤n≤50000  0≤Ai≤1e9 基本思路: 最朴素的思想就是算出所有顺序对所有逆序对…

题目链接:http://acm.hdu.edu.cn/showproblem.php?pid=4417 把数字离散化,一个查询拆成两个查询,每次查询一个前缀的和.主要问题是这个数组是静态的,如果带修改操作就不能离线了. //http://acm.hdu.edu.cn/showproblem.php?pid=4417 #include<bits/stdc++.h> using namespace std; ; int tree[maxn]; int N; int lowbit(int x) {…

思路:这题的思路很容易想到,把所有时间点离散化,然后按时间一步一步来,当到达时间i的时候处理所有在i处的查询. 这个代码怎一个挫字了得 #include<iostream> #include<cstdio> #include<cstring> #include<algorithm> #include<vector> #define Maxn 100010 #define lowbit(x) (x&(-x)) using namespace…

#include<cstdio> #include<cstring> #include<algorithm> #define ll long long using namespace std; struct node { ll x,h; } Tr[]; ],tr2[]; bool cmp(node s1,node s2) { return s1.x<s2.x; } bool cmp1(node s1,node s2) { return s1.h<s2.h;…

#include<iostream> #include<algorithm> #include<cstring> #include<cstdio> using namespace std; typedef long long ll; ; int a[N]; int ra[N]; int tr[N]; int n,x,y; int sz; int lowbit(int x) { return x&-x; } void add(int x,int c)…

Group Time Limit: 4000/2000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1959    Accepted Submission(s): 1006 Problem Description There are n men ,every man has an ID(1..n).their ID is unique. Whose ID is i and i…

Rabbit Kingdom Time Limit: 6000/3000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others) Total Submission(s): 1999    Accepted Submission(s): 689 Problem Description Long long ago, there was an ancient rabbit kingdom in the forest. Every ra…