C. Meme Problem

题目连接
C. Meme Problem
time limit per test
1 second
memory limit per test
256 megabytes
input
standard input
output
standard output

Try guessing the statement from this picture:

You are given a non-negative integer d
. You have to find two non-negative real numbers a and b such that a+b=d and a⋅b=d

.
Input

The first line contains t
(1≤t≤103

) — the number of test cases.

Each test case contains one integer d
(0≤d≤103)

.
Output

For each test print one line.

If there is an answer for the i
-th test, print “Y”, and then the numbers a and b

.

If there is no answer for the i

-th test, print “N”.

Your answer will be considered correct if |(a+b)−a⋅b|≤10−6
and |(a+b)−d|≤10−6

.
Example
Input
Copy

7
69
0
1
4
5
999
1000

Output
Copy

Y 67.985071301 1.014928699
Y 0.000000000 0.000000000
N
Y 2.000000000 2.000000000
Y 3.618033989 1.381966011
Y 997.998996990 1.001003010
Y 998.998997995 1.001002005

只是一道解二元一次方程的题。因为a+b=d,所以b=d-a;又因为ab=d,所以a(d-a)=d, 得到aa-ad+d=0;解关于a的一元二次方程。

#include<stdio.h>
#include<math.h>
#include<string.h>
#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;
int main()
{
    int t;
    scanf("%d",&t);
    while(t--)
    {
        double d,a,b;
        scanf("%lf",&d);
        if(d*d-4*d<0)
        {
            printf("N\n");
        }
        else
        {
            a=(d+sqrt(d*d-4*d))/2;
            printf("Y %.9f %.9f\n",a,d-a);
        }
    }
    return 0;
}