CF617E XOR and Favorite Number

已知一个序列 \(a_1,\ a_2,\ \cdots,\ a_n\) 和 \(k\) ，\(m\) 次询问给出 \(l,\ r\) ，求 \(\displaystyle\sum_{i=l}^r\sum_{j=i}^r[a_x\oplus a_{x+1}\oplus \cdots \oplus a_y=k]\)

\(n,\ m\leq10^5,\ 0\leq a_i,\ k\leq10^6\)

莫队

重题 bzoj5301 [CQOI2018]异或序列

考虑维护一个异或前缀和，问题就转化为了：区间 \([l-1,\ r]\) 中，有多少对数异或和为 \(k\)。莫队开桶记录即可

注意数组空间大小以及 \(long\ long\)

时间复杂度 \(O(n\sqrt n)\)

#include <bits/stdc++.h>
using namespace std;typedef long long ll;
const int maxn = 1e5 + 10;
int n, m, k, sz, a[maxn], bl[maxn], cnt[maxn * 20]; ll now, ans[maxn];
struct node {int l, r, tid;bool operator < (const node& o) const {return bl[l] != bl[o.l] ? l < o.l : r > o.r;}
} q[maxn];void add(int x) { now += cnt[x ^ k], cnt[x]++; }
void del(int x) { cnt[x]--, now -= cnt[x ^ k]; }int main() {scanf("%d %d %d", &n, &m, &k), sz = sqrt(n);for (int i = 1; i <= n; i++) {scanf("%d", a + i), a[i] ^= a[i - 1], bl[i] = (i - 1) / sz + 1;}for (int i = 1; i <= m; i++) {scanf("%d %d", &q[i].l, &q[i].r), q[i].l--, q[i].tid = i;}sort(q + 1, q + m + 1);int l = 0, r = -1;for (int i = 1; i <= m; i++) {while (q[i].l < l) add(a[--l]);while (q[i].r > r) add(a[++r]);while (q[i].l > l) del(a[l++]);while (q[i].r < r) del(a[r--]);ans[q[i].tid] = now;}for (int i = 1; i <= m; i++) {printf("%I64d\n", ans[i]);}return 0;
}

转载于:https://www.cnblogs.com/Juanzhang/p/10345401.html

CF617E XOR and Favorite Number相关推荐

CF617E. XOR and Favorite Number
1 /* 2 CF617E. XOR and Favorite Number 3 http://codeforces.com/contest/617/problem/E 4 莫队算法 5 题意:求l, ...
CodeForces 617 E. XOR and Favorite Number
题目链接: CodeForces 617 E. XOR and Favorite Number 题目描述: 给出n个数,m次查询,每次查询在区间[l, r]里面有多少对(i, j),满足ai ^ ai ...
Codeforces617E XOR and Favorite Number (普通莫队)
题目链接: XOR and Favorite Number 2021.11.11更新了解题思路和代码大致题意给定一个长度为nnn的序列aaa, 和一个固定的数值kkk. 有mmm次询问, 每次询问 ...
【CF 617E】 XOR and Favorite Number （Mo's algorithm）
[CF 617E] XOR and Favorite Number (Mo's algorithm) E. XOR and Favorite Number time limit per test 4 ...
XOR and Favorite Number（CF-617E）
Problem Description Bob has a favorite number k and ai of length n. Now he asks you to answer m quer ...
Codeforces 617E XOR and Favorite Number
Discription Bob has a favorite number k and ai of length n. Now he asks you to answer m queries. Eac ...
CodeForces - 617E XOR and Favorite Number （莫队+前缀和）
Bob has a favorite number k and ai of length n. Now he asks you to answer m queries. Each query is g ...
codeforces 617E XOR and Favorite Number 莫队
https://vjudge.net/problem/CodeForces-617E 题目大意:给nnn个数,mmm个询问,以及一个数kkk,每次询问要输出[l,r][l,r][l,r]内满足a[i] ...
CodeForces -617E XOR and Favorite Number（莫队）
题目链接:点击这里题目大意: 给定一个长度为 nnn 的序列 a1,a2,...,ana_1,a_2,...,a_na1,a2,...,an ,再给出一个数字 kkk , mmm 组询问每组询 ...

CF617E XOR and Favorite Number

CF617E XOR and Favorite Number相关推荐

最新文章

热门文章