码迷,mamicode.com
首页 > 其他好文 > 详细

hdoj 2199 Can you solve this equation?【浮点型数据二分】

时间:2015-07-30 13:19:00      阅读:97      评论:0      收藏:0      [点我收藏+]

标签:

Can you solve this equation?

Time Limit: 2000/1000 MS (Java/Others)    Memory Limit: 32768/32768 K (Java/Others)
Total Submission(s): 12766    Accepted Submission(s): 5696


Problem Description
Now,given the equation 8*x^4 + 7*x^3 + 2*x^2 + 3*x + 6 == Y,can you find its solution between 0 and 100;
Now please try your lucky.
 

 

Input
The first line of the input contains an integer T(1<=T<=100) which means the number of test cases. Then T lines follow, each line has a real number Y (fabs(Y) <= 1e10);
 

 

Output
For each test case, you should just output one real number(accurate up to 4 decimal places),which is the solution of the equation,or “No solution!”,if there is no solution for the equation between 0 and 100.
 

 

Sample Input
2
100
-4
 

 

Sample Output
1.6152
No solution!
#include<stdio.h>
#include<string.h>
double f(double v)//用来计算方程结果(即y的值) 
{
	return 8*v*v*v*v+7*v*v*v+2*v*v+3*v+6;
}
int main()
{
	int t;
	double y,l,r,mid;
	scanf("%d",&t);
	while(t--)
	{
		scanf("%lf",&y);
		if(y<f(0)||y>f(100))
		{
			printf("No solution!\n");
			continue;
		}
		l=0;r=100;mid=0;
		while((r-l) > 1e-10)//题目要求精度为小数点后四位,最好把精度调高 
		{
			mid=(l+r)/2;//每次折半取x的范围 
			if(f(mid) < y) 
			    l=mid;
			else
			    r=mid;
		}
		printf("%.4lf\n",mid);
	}
}

  

hdoj 2199 Can you solve this equation?【浮点型数据二分】

标签:

原文地址:http://www.cnblogs.com/tonghao/p/4688714.html

(0)
(0)
   
举报
评论 一句话评论(0
登录后才能评论!
© 2014 mamicode.com 版权所有  联系我们:gaon5@hotmail.com
迷上了代码!