zoukankan      html  css  js  c++  java
  • HDU 2604 Queuing(矩阵快速幂)

    Queuing

    Time Limit: 10000/5000 MS (Java/Others) Memory Limit: 32768/32768 K (Java/Others)
    Total Submission(s): 4237 Accepted Submission(s): 1879

    Problem Description
    Queues and Priority Queues are data structures which are known to most computer scientists. The Queue occurs often in our daily life. There are many people lined up at the lunch time.

    Now we define that ‘f’ is short for female and ‘m’ is short for male. If the queue’s length is L, then there are 2L numbers of queues. For example, if L = 2, then they are ff, mm, fm, mf . If there exists a subqueue as fmf or fff, we call it O-queue else it is a E-queue.
    Your task is to calculate the number of E-queues mod M with length L by writing a program.

    Input
    Input a length L (0 <= L <= 10 6) and M.

    Output
    Output K mod M(1 <= M <= 30) where K is the number of E-queues with length L.

    Sample Input
    3 8
    4 7
    4 8

    Sample Output
    6
    2
    1

    找到递推关系
    s[n]=s[n-1]+s[n-3]+s[n-4];

    #include <iostream>
    #include <string.h>
    #include <stdio.h>
    #include <algorithm>
    #include <math.h>
    #include <stdlib.h>
    
    using namespace std;
    struct Node
    {
        int a[10][10];
    };
    int n,m;
    Node multiply(Node a,Node b)
    {
        Node c;
        memset(c.a,0,sizeof(c.a));
        for(int i=0;i<4;i++)
        {
            for(int j=0;j<4;j++)
            {
                if(!a.a[i][j]) continue;
                for(int k=0;k<4;k++)
                {
                    (c.a[i][k]+=(a.a[i][j]*b.a[j][k])%m)%=m;
                }
            }
        }
        return c;
    }
    Node get(Node a,int x)
    {
        Node c;
        memset(c.a,0,sizeof(c.a));
        for(int i=0;i<4;i++)
            c.a[i][i]=1;
        for(x;x;x>>=1)
        {
            if(x&1) c=multiply(c,a);
            a=multiply(a,a);
        }
        return c;
    }
    int main()
    {
        while(scanf("%d%d",&n,&m)!=EOF)
        {
        if(n==0)
        {printf("1
    ");continue;}
        else if(n==1)
        {printf("2
    ");continue;}
        else if(n==2)
        {printf("4
    ");continue;}
        else if(n==3)
        {printf("6
    ");continue;}
        else
        {
            Node a;
            a.a[0][0]=1;a.a[0][1]=0;a.a[0][2]=1;a.a[0][3]=1;
            a.a[1][0]=1;a.a[1][1]=0;a.a[1][2]=0;a.a[1][3]=0;
            a.a[2][0]=0;a.a[2][1]=1;a.a[2][2]=0;a.a[2][3]=0;
            a.a[3][0]=0;a.a[3][1]=0;a.a[3][2]=1;a.a[3][3]=0;
            Node b;
            memset(b.a,0,sizeof(b.a));
            b.a[0][0]=6;b.a[1][0]=4;b.a[2][0]=2;b.a[3][0]=1;
            a=get(a,n-3);
            a=multiply(a,b);
            printf("%d
    ",a.a[0][0]);
    
        }
    
        }
        return 0;
    
    }
  • 相关阅读:
    基于WINCE.NET4.2系统的PDA使用PPC2003软件全攻略
    中文语方SQL脚本1(原创)
    debian下NAT的设置
    一个用于 MRTG 自动告警的脚本 (ZT)
    debian 4配置snmpd(有特别注意地方)
    [ZT]半小时精通正则表达式
    怎么把CSDN上的文章及图片导出到本地?
    zookeeper 简介
    Linux之搜索查找类指令
    Java之文档注释基本使用
  • 原文地址:https://www.cnblogs.com/dacc123/p/8228698.html
Copyright © 2011-2022 走看看