Problem Description
With given integers a,b,c, you are asked to judge whether the following statement is true: "For any x, if a⋅+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
Hint
Source
"Inspur Cup" Shandong Province 8th ACM College Student Programming Competition (Thanks to Qingdao University of Science and Technology)
The meaning of the question: give you a logical formula, give a, b, c, so that you can judge whether this logical formula is right or wrong;
Ideas:
As long as there is x in the formula a*x*x+b*x+c==0, then x must be an integer, that is:
p q p->q
0 0 1
0 1 1
1 0 0
1 1 1
#include<cstdio> #include<cstring> #include<algorithm> using namespace std; int main(){ int T; scanf("%d",&T); while(T--){ double a,b,c; scanf("%lf%lf%lf",&a,&b,&c); if(a==0&&b==0){ if(c==0) printf("NO\n"); //When a=b=c=0, all x are matched, so it is NO else printf("YES\n");//c!=0, the former formula is 0, no matter what the value of the latter formula is, the result is 0 } else if(a==0){ if((-c/b)==(int)(-c/b)) printf("YES\n"); else printf("NO\n"); } else if(b*b-4*a*c>=0){ int flag=0; for(int i=-5;i<=5;i++) if(a*i*i+b*i+c==0) flag++; if(b*b-4*a*c==0&&flag==1) printf("YES\n"); else if(b*b-4*a*c>0&&flag==2) printf("YES\n"); else printf("NO\n"); } else printf("YES\n"); } return 0; }