Poj 1840 EQS (violent)

Source: Internet
Author: User

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, xiε [-50, 50], Xi! = 0, any I ε {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 in 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

Naked brute force question: five cycles were opened during the competition, and the time was limited to 5 seconds. I thought it was impossible to run locally.

Short is used for the first time.

#include<iostream>#include<cstdio>#include<cstring>#include<algorithm>#include<limits.h>typedef long long LL;using namespace std;                        short hash[25000001];int a1,a2,a3,a4,a5;int main(){    while(~scanf("%d%d%d%d%d",&a1,&a2,&a3,&a4,&a5))    {        int ans=0;        memset(hash,0,sizeof(hash));        for(int x1=-50;x1<=50;x1++)        {            if(x1==0)               continue;            for(int x2=-50;x2<=50;x2++)            {                if(x2==0)                    continue;                int s=(-1)*(a1*x1*x1*x1+a2*x2*x2*x2);                if(s<0)                    s+=25000000;                hash[s]++;            }        }        for(int x1=-50;x1<=50;x1++)        {            if(x1==0)               continue;            for(int x2=-50;x2<=50;x2++)            {                if(x2==0)                    continue;                for(int x3=-50;x3<=50;x3++)                {                    if(x3==0)                        continue;                    int s=a3*x1*x1*x1+a4*x2*x2*x2+a5*x3*x3*x3;                    if(s<0)                        s+=25000000;                    if(hash[s])                        ans+=hash[s];                }            }        }        printf("%d\n",ans);    }    return 0;}



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