POJ 1840 --EQS
来源:互联网 发布:python excel数据处理 编辑:程序博客网 时间:2024/06/15 08:31
Language:
Eqs
Time Limit: 5000MS Memory Limit: 65536KTotal Submissions: 13934 Accepted: 6840
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.
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
首先 题目的意思就是解一个 五元3次的方程 求满足等式的解的个数;
直接暴力循环求解呢,肯定会超时的;
可以将5层循环 拆分成一个2层的和一个3层的 他们的值是相反数 ,这样的话时间会减少;
保存前2项和的同时 也要记得保存 出现这个和的可能的解得个数;
也就是 hash 求值 ;
当然,注意一个特殊条件 , 各值不能存在0;
#include <iostream>#include <cstring>using namespace std;short hash[25000001]; //hash [sum] 表示值等于sum 的解的数目int main(){ int a1, a2, a3, a4, a5; while ( cin >> a1>>a2>>a3>>a4>>a5){ memset(hash, 0, sizeof(hash)) ; for ( int x1 = -50 ; x1 <= 50; x1 ++ ) { if ( !x1) continue ; for ( int x2 = -50 ; x2 <= 50 ; x2 ++) { if (!x2) continue; int sum = (a1 *x1*x1*x1 + a2*x2*x2*x2) *(-1); if ( sum < 0 ) sum += 25000000; hash[sum] ++ ; } } int solution = 0 ; for ( int x3 = -50 ; x3 <=50 ; x3 ++ ) { if (!x3) continue ; for ( int x4 = -50 ; x4 <= 50 ; x4 ++ ) { if (!x4) continue ; for ( int x5 = -50 ; x5 <= 50 ; x5 ++ ) { if (!x5) continue ; int sum = a3*x3*x3*x3 + a4 *x4*x4*x4 + a5*x5*x5*x5 ; if ( sum < 0 ) sum += 25000000; if ( hash[sum ]) solution += hash[sum ]; } } } cout <<solution << endl ; } return 0;}
0 0
- poj 1840 Eqs
- POJ 1840 Eqs
- poj 1840 Eqs
- POJ 1840 Eqs
- POJ 1840 Eqs hash
- POJ-1840 Eqs【Hash】
- poj 1840 Eqs 【hash】
- POJ 1840 Eqs
- poj-1840 Eqs
- POJ 1840 Eqs
- POJ 1840 Eqs
- poj 1840 Eqs
- POJ 1840 Eqs
- POJ 1840 Eqs
- POJ 1840(Eqs)
- POJ 1840 Eqs
- POJ 1840 Eqs
- POJ 1840 Eqs
- 整合:图论存图方法及三种重要做法分析(Kruskal Dijkstra Bellman-Ford)
- Quartz异常的一些处理
- 为什么用‘=’符号代表赋值,而不是‘:=’或‘==’?
- 如何选择靠谱的短信验证码服务商
- sql server日期时间函数
- POJ 1840 --EQS
- 1:ActionBar
- 图片保存到数据库的方法
- iOS画线粗细
- 消息中间件(二)---ActiveMQ
- CGI与Servlet的比较
- android_Activity的四种启动模式和onNewIntent()
- 图片循环滚动代码(无缝滚动)(分别向上、下、左、右)
- android.support.design.widget.TabLayout