Educational Codeforces Round 24 E
Vova again tries to play some computer card game.
The rules of deck creation in this game are simple. Vova is given an existing deck of n cards and a magic number k. The order of the cards in the deck is fixed. Each card has a number written on it; number ai is written on the i-th card in the deck.
After receiving the deck and the magic number, Vova removes x (possibly x = 0) cards from the top of the deck, y (possibly y = 0) cards from the bottom of the deck, and the rest of the deck is his new deck (Vova has to leave at least one card in the deck after removing cards). So Vova's new deck actually contains cards x + 1, x + 2, ... n - y - 1, n - y from the original deck.
Vova's new deck is considered valid iff the product of all numbers written on the cards in his new deck is divisible by k. So Vova received a deck (possibly not a valid one) and a number k, and now he wonders, how many ways are there to choose x and y so the deck he will get after removing x cards from the top and y cards from the bottom is valid?
The first line contains two integers n and k (1 ≤ n ≤ 100 000, 1 ≤ k ≤ 109).
The second line contains n integers a1, a2, ..., an (1 ≤ ai ≤ 109) — the numbers written on the cards.
Print the number of ways to choose x and y so the resulting deck is valid.
3 4
6 2 8
4
3 6
9 1 14
1
In the first example the possible values of x and y are:
- x = 0, y = 0;
- x = 1, y = 0;
- x = 2, y = 0;
- x = 0, y = 1;
题意:选取一段区间,使得乘积形式%k==0,选法有多少种
解法:
1 确定是否被k整除,可以分解质因数或者选择A1*%k*A2*%k....是不是等于0
2 选择第二种方法,求区间乘积,利用线段树维护(当然如果时间给的短就是另一回事了QUQ 第二个代码给出双指针做法,时间更短)
3 寻找符合条件的区间
3.1 如果i~(l+r)/2区间符合,则r=mid,不符合l=mid+1
3.2 最后得出来的区间也必须符合
4 我们避免计算重复,只计算 n-pos+1次数
#include <iostream>
#include <cstring>
#include <cstdio>
using namespace std;
int n,m;
const int Max=1e6;
long long Arr[Max];
long long Pos[Max*];
#define lson l,mid,rt<<1
#define rson mid+1,r,rt<<1|1
void Build(int rt,int l,int r){
if(l==r){
Pos[rt]=Arr[l]%m;
return;
}
int mid=(l+r)/;
Build(rt*,l,mid);
Build(rt*+,mid+,r);
Pos[rt]=(Pos[rt*]*Pos[rt*+])%m;
}
long long query(int L,int R,int l,int r,int rt){
if(L<=l&&r<=R){
return Pos[rt];
}
long long ans=;
int mid=(l+r)/;
if(mid>=L){
ans*=query(L,R,l,mid,rt*)%m;
}
if(mid<R){
ans*=query(L,R,mid+,r,rt*+)%m;
}
return ans%m;
}
int main()
{
scanf("%d%d",&n,&m);
for(int i=;i<=n;i++){
scanf("%lld",&Arr[i]);
}
Build(,,n);
long long Sum=;
for(int i=;i<=n;i++){
int l=i;
int r=n;
int pos=n;
while(l<r){
int mid=(l+r)/;
if(query(i,mid,,n,)%m==){
pos=mid;
r=mid;
}else{
l=mid+;
}
}
if(query(i,pos,,n,)%m==){
Sum+=(n-pos+);
}
}
printf("%lld\n",Sum);
return ;
}
http://codeforces.com/contest/818/submission/28156236
#include <bits/stdc++.h>
#include <ext/hash_map>
#include <ext/numeric> using namespace std;
using namespace __gnu_cxx; #define REP(i,n) for( (i)=0 ; (i)<(n) ; (i)++ )
#define rep(i,x,n) for( (i)=(x) ; (i)<(n) ; (i)++ )
#define REV(i,n) for( (i)=(n) ; (i)>=0 ; (i)-- )
#define FORIT(it,x) for( (it)=(x).begin() ; (it)!=(x).end() ; (it)++ )
#define foreach(it,c) for(__typeof((c).begin()) it=(c).begin();it!=(c).end();++it)
#define rforeach(it,c) for(__typeof((c).rbegin()) it=(c).rbegin();it!=(c).rend();++it)
#define foreach2d(i, j, v) foreach(i,v) foreach(j,*i)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define SZ(x) ((int)(x).size())
#define MMS(x,n) memset(x,n,sizeof(x))
#define mms(x,n,s) memset(x,n,sizeof(x)*s)
#define pb push_back
#define mp make_pair
#define NX next_permutation
#define UN(x) sort(all(x)),x.erase(unique(all(x)),x.end())
#define CV(x,n) count(all(x),(n))
#define FIND(x,n) find(all(x),(n))-(x).begin()
#define ACC(x) accumulate(all(x),0)
#define PPC(x) __builtin_popcountll(x)
#define LZ(x) __builtin_clz(x)
#define TZ(x) __builtin_ctz(x)
#define mxe(x) *max_element(all(x))
#define mne(x) *min_element(all(x))
#define low(x,i) lower_bound(all(x),i)
#define upp(x,i) upper_bound(all(x),i)
#define NXPOW2(x) (1ll << ((int)log2(x)+1))
#define PR(x) cout << #x << " = " << (x) << endl ; typedef unsigned long long ull;
typedef long long ll;
typedef vector<int> vi;
typedef vector<vector<int> > vvi;
typedef pair<int, int> pii; const int OO = (int) 2e9;
const double eps = 1e-; const int N = ; int n, k;
int a[N]; int main() {
std::ios_base::sync_with_stdio(false);
cin.tie(NULL);
cout.tie(NULL);
#ifndef ONLINE_JUDGE
// freopen("in.txt", "rt", stdin);
// freopen("out.txt", "wt", stdout);
#endif
cin >> n >> k;
for (int i = ; i < n; i++) {
cin >> a[i];
}
int st = , en = ;
ll res = ;
int prv = -;
while (en < n) {
ll cur = ;
for (int i = st; i < n; i++) {
cur *= a[i];
cur %= k;
if (cur == ) {
en = i;
break;
}
}
if (cur != ) {
break;
}
cur = ;
for (int i = en; i >= ; i--) {
cur *= a[i];
cur %= k;
if (cur == ) {
st = i;
break;
}
}
if (cur == ) {
//cout << st << " " << en << endl;
res += (st - prv) * 1LL * (n - en);
prv = st;
}
st++;
en++;
}
cout << res << endl;
return ;
}
Educational Codeforces Round 24 E的更多相关文章
- Educational Codeforces Round 24 A 水 B stl C 暴力 D stl模拟 E 二分
A. Diplomas and Certificates time limit per test 1 second memory limit per test 256 megabytes input ...
- Educational Codeforces Round 24 CF 818 A-G 补题
6月快要结束了 期末也过去大半了 马上就是大三狗了 取消了小学期后20周的学期真心长, 看着各种北方的学校都放假嗨皮了,我们这个在北回归线的学校,还在忍受酷暑. 过年的时候下定决心要拿块ACM的牌子, ...
- codeforces Educational Codeforces Round 24 (A~F)
题目链接:http://codeforces.com/contest/818 A. Diplomas and Certificates 题解:水题 #include <iostream> ...
- Educational Codeforces Round 24
A. Diplomas and Certificates time limit per test 1 second memory limit per test 256 megabytes input ...
- Educational Codeforces Round 24 D
Alice and Bob got very bored during a long car trip so they decided to play a game. From the window ...
- Educational Codeforces Round 24 B
n children are standing in a circle and playing a game. Children's numbers in clockwise order form a ...
- Educational Codeforces Round 24 A
There are n students who have taken part in an olympiad. Now it's time to award the students. Some o ...
- Educational Codeforces Round 24 题解
A: 考你会不会除法 //By SiriusRen #include <bits/stdc++.h> using namespace std; #define int long long ...
- Educational Codeforces Round 32
http://codeforces.com/contest/888 A Local Extrema[水] [题意]:计算极值点个数 [分析]:除了第一个最后一个外,遇到极值点ans++,包括极大和极小 ...
随机推荐
- vue 安装与起步
vue安装: 1.官网下载vue,在script标签里引用(去下载) 2.使用CDN(建议下载到本地,不推荐这种方法): BootCDN:https://cdn.bootcss.com/vue/2.2 ...
- HDOJ 5045 Contest
状压DP.. . . Contest Time Limit: 2000/1000 MS (Java/Others) Memory Limit: 65536/65536 K (Java/Other ...
- iOS中区分照片的来源
原理就是通过枚举出每个assets group,然后取得group property,group property是个整数,对应头文件中的一些枚举值.用这个可以判断照片是从哪来的(相机胶卷.照片流.相 ...
- react native与原生的交互
一.交互依赖的重要组件 react native 中如果想要调用ios 中相关的方法,必须依赖一个重要的组件nativemodules import { NativeModules } from ' ...
- YTU 1055: 输入字符串以及输出
1055: 输入字符串以及输出 时间限制: 1 Sec 内存限制: 128 MB 提交: 694 解决: 476 题目描述 编写一函数,由实参传来一个字符串,统计此字符串中字母.数字.空格和其它字 ...
- 栏目抓取网站日kafka
#!/usr/bin/python3#-*- coding:utf-8 -*-"""create 2018-02-27author zldesc: https://ind ...
- 使用masonry手写约束
在iOS开发过程中,手写contraints是非常痛苦的一件事情,往往那么一丢丢功能要写大量的代码,非常容易发生错误,并且非常不方便调试.所以只有在不得以的情况下才采用手工方式写contraints, ...
- JAVA泛型与可变参数
泛型的引入: 早期的Object类型可以接收任意的对象类型,但是在实际的使用中,会有类型转换的问题.也就存在这隐患,所以Java提供了泛型来解决这个安全问题. 格式: 泛型类:public class ...
- bzoj3998
后缀自动机+dp 想了挺长时间 后缀自动机的状态图是一个dag,从root走到一个点的路径数代表了这个状态包含的子串,我们先预处理出来每个节点向后走能够形成多少子串,注意这里不是直接在parent树上 ...
- 【205】C#实现远程桌面访问
参考:Remote Desktop using C#.NET 参考文件:TscForm.zip 本博客主要是讲述怎样用 .NET 平台中 Microsoft Terminal Services Cli ...