zoukankan      html  css  js  c++  java
  • POJ 1840, Eqs

    Time Limit: 5000MS  Memory Limit: 65536K
    Total Submissions: 3409  Accepted: 1514


    Description
    Consider equations having the following form:
    a1x13+ a2x23+ a3x33+ a4x43+ a5x53=0
    The coefficients are given integers from the interval [-50,50].
    It is consider a solution a system (x1, x2, x3, x4, x5) that verifies the equation, xi∈[-50,50], xi != 0, any i∈{1,2,3,4,5}.

    Determine how many solutions satisfy the given equation.

     

    Input
    The only line of input contains the 5 coefficients a1, a2, a3, a4, a5, separated by blanks.

    Output
    The output will contain on the first line the number of the solutions for the given equation.

    Sample Input
    37 29 41 43 47

    Sample Output
    654

    Source
    Romania OI 2002


    // POJ1840.cpp : Defines the entry point for the console application.
    //

    #include 
    <iostream>
    using namespace std;

    struct Node
    {
        Node():count(
    0), num(0), next(NULL){}
        
    int num;
        
    int count;
        Node
    * next;
    };

    int main(int argc, char* argv[])
    {
        
    int a[5];
        cin 
    >> a[0>> a[1>> a[2>> a[3>> a[4];

        
    const int SIZE = 33119;
        Node hash[SIZE];

        
    //create lookup table
        int X[51];
        
    for (int i = 0; i <=50++i) X[i] = i * i * i;

        
    //init hash table
        for (int i = -50; i <=50++i)
            
    for (int j = -50; j <= 50++j)
                
    if (i != 0 && j != 0)
                {
                    
    int num = a[0* (i < 0 ? -X[-i]:X[i]) + a[1* (j < 0 ? -X[-j]:X[j]);
                    
    int key = num % SIZE;
                    
    if (key < 0) key += SIZE;
                    Node
    * pt = &hash[key];
                    
    bool found = false;
                    
    while (pt->next != NULL)
                    {
                        pt 
    = pt->next;
                        
    if (pt->num == num)
                        {
                            
    ++(pt->count);
                            found 
    = true;
                            
    break;
                        }
                    }
                    
    if (found == false)
                    {
                        Node
    * pc = new Node;
                        pc
    ->count = 1;
                        pc
    ->num = num;
                        pt
    ->next = pc;        
                    };
                };

        
    //search hash table and find match
        int cnt = 0;
        
    for (int i = -50; i <=50++i)
            
    for (int j = -50; j <= 50++j)
                
    for (int k = -50; k <= 50++k)
                    
    if (i != 0 && j != 0 && k != 0)
                    {
                        
    int num = -(a[2* (i < 0 ? -X[-i]:X[i]) +
              a[3* (j < 0 ? -X[-j]:X[j]) + a[4* (k < 0 ? -X[-k]:X[k]));
                        
    int key = num % SIZE;
                        
    if (key < 0) key += SIZE;

                        Node
    * pt = &hash[key];
                        
    while (pt->next != NULL)
                        {
                            pt 
    = pt->next;
                            
    if (pt->num == num)
                            {
                                cnt 
    += pt->count;
                                
    break;
                            }
                        }
                    };

        cout 
    << cnt <<endl;
        
    return 0;
    }

  • 相关阅读:
    git的版本回退
    elementui的表格有多选框时翻页记住之前选择的数据
    git操作总结
    POJ 3107 Godfather
    HDU 4405 Aeroplane chess
    ZOJ 3626 Treasure Hunt I
    UVA 10537 Toll! Revisited
    POJ 3093 Margaritas on the River Walk
    POJ 1655 Balancing Act
    POJ 2342 Anniversary party
  • 原文地址:https://www.cnblogs.com/asuran/p/1579397.html
Copyright © 2011-2022 走看看