CodeForces - 617E 给n个数, m个询问, 每次询问问你[l, r]区间内有多少对(i, j), 使得a[i]^a[i+1]^......^a[j]结果为k.(注意 i ! =  j)维护一个前缀异或值就可以了.要注意的是 区间[l, r], 我们需要将pre[l-1]......pre[r]都加进去, pre[l-1]不能少. #include<bits/stdc++.h> using namespace std; #define maxn 1234567 #define l…

https://www.luogu.org/problemnew/show/P4462 http://codeforces.com/problemset/problem/617/E 这个是莫队裸题了吧... 然而,注意: 1.答案开longlong 2.要用桶来代替map/unordered_map,不然会T:桶的大小要大于两倍值域(这是较松的上限,实际上限就是值域内两个数异或能得到的最大值,大概就是值域转换成二进制后每一位变成1后再转回十进制得到的值吧) CF #include<cstdio>…

题意原文地址:https://blog.csdn.net/chenzhenyu123456/article/details/50574169 题意: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. 思路:离线做.首先预处理前缀异或和sum[],那么ai ^ ... ^ aj == sum[i-1] ^ sum[j]. 这样对一次查询[l, r]的处理,可以从左到右扫一次,统计…

a[i]^a[i+1]--a[j]=k; 处理前缀和pre[i] 那么上式可以表示为pre[i-1]^pre[j]=k; #include<bits/stdc++.h> using namespace std; const int N=1<<20; 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(…

题目链接: 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…

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…

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…

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…