With given integers a,b,c, you are asked to judge whether the following statement is true: "For any x, if a x2 +b⋅x+c=0, then x is an integer."
Input
The first line contains only one integer T(1≤T≤2000), which indicates the number of test cases.
For each test case, there is only one line containing three integers a,b,c(−5≤a,b,c≤5).
Output
or each test case, output “YES” if the statement is true, or “NO” if not.
Sample Input
3 1 4 4 0 0 1 1 3 1
Sample Output
YES YES NO
题意:
给你三个数,a,b,c问这三个数构成的一元二次方程有没有非整数根,(如果有根,则一定整数,如果命题成立,输出yes 否则输出no),没有根的情况为yes。
#include <iostream>
#include<cstdio>
#include<algorithm>
#include<cmath>
#define minn 1e-8
using namespace std;
int main()
{
int t,a,b,c,ans;
double ans1;
cin>>t;
while(t--)
{
cin>>a>>b>>c;
if(a==0)
{
if(b!=0)
{
if(c%b!=0)
printf("NO
");
else
printf("YES
");
}
else
{
if(c==0)
printf("NO
");
else
printf("YES
");
}
}
else
{
double der=b*b-4*a*c;
if(der<0)
{
printf("YES
");
}
else
{
double dd=sqrt(der);
int dd1=int(sqrt(der));
if(abs(dd1-dd)<minn&&((-b+dd1)%(2*a)==0&&(-b-dd1)%(2*a)==0))
printf("YES
");
else
printf("NO
");
}
}
} return 0;
}