题目大意:给你一个长度为n的序列,有m个询问,每次询问一个区间[L,R],表示这个区间内,有多少的a[i]^a[i+1].....^a[j]=k. 思路:莫队去搞就好了 我们定义pre[i]=a[1]^a[2]^....a[i],然后我们再去更新就好了,这里,我们定义区间[L,R]表示我们所要询问的区间即可.然后这里会有一个疑惑,就是为什么while(l<Q[i].l) { Delete(l-1); l++; }和while(l>Q[i].l) { l--; Updata(l-1); }是这样…

[Codeforces Round #340 (Div. 2)] vp了一场cf..(打不了深夜的场啊!!) A.Elephant 水题,直接贪心,能用5步走5步. B.Chocolate 乘法原理计数,统计连续的“0”到下一个“1”的个数,然后相乘(第一个1前面的0不能算上).当然还要特判全0的情况. C.Watering Flowers 这题1A.只要按照以到某一个喷泉的距离排序,然后枚举没有被这一个喷泉覆盖到的个数,然后通过第二个喷泉覆盖,贪心一下就好了. D.Polyline 题意杀,还…

E. XOR and Favorite Number 题目连接: http://www.codeforces.com/contest/617/problem/E Descriptionww.co Bob has a favorite number k and ai of length n. Now he asks you to answer m queries. Each query is given by a pair li and ri and asks you to count the n…

任意门:http://codeforces.com/problemset/problem/617/E E. XOR and Favorite Number time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Bob has a favorite number k and ai of length n. Now he asks yo…

题目链接:http://codeforces.com/problemset/problem/617/E E. XOR and Favorite Number time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Bob has a favorite number k and ai of length n. Now he asks y…

题目链接:http://codeforces.com/contest/617/problem/E 题目大意:有n个数和m次查询,每次查询区间[l, r]问满足ai ^ ai+1 ^ ... ^ aj == k的(i, j)  (l <= i <= j <= r)有多少对. 解题思路:先预处理出一个前缀异或和数组sum数组,则a[l]^a[l+1]^a[l+2]……^a[r]就等于sum[r]^sum[l-1] 然后我们采用莫队算法,用一个数组cnt数组记录前缀和出现的次数 我们要找之前有…

E. XOR and Favorite Number time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Bob has a favorite number k and ai of length n. Now he asks you to answer m queries. Each query is given by a pai…

time limit per test 4 seconds memory limit per test 256 megabytes input standard input output standard output Bob has a favorite number k and ai of length n. Now he asks you to answer m queries. Each query is given by a pair li and ri and asks you to…

#include<bits/stdc++.h> using namespace std; <<; struct node{ int l,r; int id; }q[N]; int pos[N]; long long ans[N]; //每个前缀值出现的次数 long long flag[N]; int a[N]; bool cmp(node a,node b) { //如果左端点在同一块中,按右端点排序 if(pos[a.l]==pos[b.l]) return a.r<b.…

C. Watering Flowers 题目连接: http://www.codeforces.com/contest/617/problem/C Descriptionww.co A flowerbed has many flowers and two fountains. You can adjust the water pressure and set any values r1(r1 ≥ 0) and r2(r2 ≥ 0), giving the distances at which t…