Hdu6078Wavel Sequence

来源：互联网发布：淘宝手机排名突然没了编辑：程序博客网时间：2024/04/28 12:21

Wavel Sequence

Time Limit: 4000/2000 MS (Java/Others) Memory Limit: 524288/524288 K (Java/Others)
Total Submission(s): 582 Accepted Submission(s): 301

Problem Description

Have you ever seen the wave? It's a wonderful view of nature. Little Q is attracted to such wonderful thing, he even likes everything that looks like wave. Formally, he defines a sequence

a1,a2,...,an as ''wavel'' if and only if

a1<a2>a3<a4>a5<a6...

Picture from Wikimedia Commons

Now given two sequences

a1,a2,...,an and

b1,b2,...,bm, Little Q wants to find two sequences

f1,f2,...,fk(1≤fi≤n,fi<fi+1) and

g1,g2,...,gk(1≤gi≤m,gi<gi+1), where

afi=bgi always holds and sequence

af1,af2,...,afk is ''wavel''.

Moreover, Little Q is wondering how many such two sequences

f and

g he can find. Please write a program to help him figure out the answer.

Input

The first line of the input contains an integer

T(1≤T≤15), denoting the number of test cases.

In each test case, there are

2 integers

n,m(1≤n,m≤2000) in the first line, denoting the length of

a and

b.

In the next line, there are

n integers

a1,a2,...,an(1≤ai≤2000), denoting the sequence

a.

Then in the next line, there are

m integers

b1,b2,...,bm(1≤bi≤2000), denoting the sequence

Output

For each test case, print a single line containing an integer, denoting the answer. Since the answer may be very large, please print the answer modulo

998244353.

Sample Input

13 51 5 34 1 1 5 3

Sample Output

10Hint
(1)f=(1),g=(2).(2)f=(1),g=(3).(3)f=(2),g=(4).(4)f=(3),g=(5).(5)f=(1,2),g=(2,4).(6)f=(1,2),g=(3,4).(7)f=(1,3),g=(2,5).(8)f=(1,3),g=(3,5).(9)f=(1,2,3),g=(2,4,5).(10)f=(1,2,3),g=(3,4,5).

Source

2017 Multi-University Training Contest - Team 4

——————————————————————————————————

题意：规定a1< a2 > a3 < a4 > a5 < a6……的数组为波浪数组，且第一个数必须为波谷，给定数组a，b，找出a中的波浪数组在b中有几组存在

解题思路：dp[i][0]存放b[i]作为波谷时的情况，dp[i][1]存放b[i]作为波峰时的情况。然后枚举a数组，在b数组中去找和a[i]一样的位置，找到后更新答案

#include <stdio.h>#include <stdlib.h>#include <string.h>#include <string>#include <math.h>#include <time.h>#include <algorithm>#include <complex>#include <vector>#include <stack>#include <queue>#include <map>#include <set>using namespace std;#define LL long long#define mem(a,b) memset(a,b,sizeof a);const int inf=0x3f3f3f3f;const LL llinf=0x3f3f3f3f3f3f3f3f;const double pi=acos(-1.0);const double eps=1e-8;const LL mod=998244353;const int maxn=2010;LL dp[maxn][2];int a[maxn],b[maxn];int main(){    int T;    int n,m;    for(scanf("%d",&T); T--;)    {        mem(dp,0);        scanf("%d%d",&n,&m);        for(int i=1; i<=n; i++)            scanf("%d",&a[i]);        for(int i=1; i<=m; i++)            scanf("%d",&b[i]);        LL ans=0;         mem(dp,0);        for(int i=1; i<=n; i++)        {            LL l=1,h=0;            for(int j=1; j<=m; j++)            {                if(a[i]==b[j])                {                    dp[j][0]+=l,dp[j][1]+=h;                    ans=(ans+(l+h)%mod)%mod;                }                else if(b[j]<a[i]) h=(h+dp[j][0])%mod;                else l=(l+dp[j][1])%mod;            }        }        printf("%lld\n",ans);    }    return 0;}