Poj 1840 simple hash and poj1840hash
Http://poj.org/problem? Id = 1840
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
/** Poj 1840 hash */# include <stdio. h> # include <string. h >#include <iostream >#include <algorithm> using namespace std; typedef long LL; const int maxn = 25000008; int a1, a2, a3, a4, a5; short hash [maxn * 2]; // int will kill the memory constraint. The space complexity is very tight. int main () {while (cin> a1> a2> a3> a4> a5) {for (int I =-50; I <= 50; I ++) {if (I = 0) continue; for (int j =-50; j <= 50; j ++) {if (j = 0) continue; for (int k =-50; k <= 50; k ++) {if (k = 0) continue; hash [I * a1 + j * a2 + k * a3 + maxn] ++ ;}} LL ans = 0; for (int I =-50; I <= 50; I ++) {if (I = 0) continue; for (int j =-50; j <= 50; j ++) {if (j = 0) continue; ans + = hash [-I * a4-j * j * a5 + maxn];} cout <ans <endl;} return 0 ;}