hdoj 1840 Equations

Equations

Time Limit: 1000/1000 MS (Java/Others)    Memory Limit: 65535/65535 K (Java/Others)
Total Submission(s): 1001    Accepted Submission(s): 458

Problem Description

All the problems in this contest totally bored you. And every time you get bored you like playing with quadratic equations of the form a*X² + b*X + c = 0. This time you are very curious to know how many real solutions an equation of this type has.

Input

The first line of input contains an integer number Q, representing the number of equations to follow. Each of the next Q lines contains 3 integer numbers, separated by blanks, a, b and c, defining an equation. The numbers are from the interval [-1000,1000].

Output

For each of the Q equations, in the order given in the input, print one line containing the number of real solutions of that equation. Print “INF” (without quotes) if the equation has an infinite number of real solutions.

Sample Input

3
1 0 0
1 0 -1
0 0 0

Sample Output

1
2
INF

水题：

 

#include<stdio.h>
#include<string.h>
int main()
{
    int t;
    double a,b,c,d;
    scanf("%d",&t);
    while(t--)
    {
        scanf("%lf%lf%lf",&a,&b,&c);
        d=b*b-4*a*c;
        if(a!=0)
        {
            if(d>0) 
            printf("2\n");
            else if(d<0)
            printf("0\n");
            else
            printf("1\n");
        }
        else
        {
            if(b==0&&c==0)
            printf("INF\n");
            else if(b==0&&c!=0)
            printf("0\n");
            else if(b!=0&&c!=0)
            printf("1\n");
            else
            printf("1\n");
        }
    }
    return 0;
}