HUST 1541 Student’s question
2019-06-06
08:47:59
坚持！！！
1 #include <bits/stdc++.h> 2 using namespace std; 3 int main() 4 { 5 int n; 6 scanf("%d", &n); 7 while (n--) 8 { 9 int a,b,c; 10 scanf("%d %d %d", &a, &b, &c); 11 int m = b * b - 4 * a * c; 12 if(m < 0) 13 cout << "NO"; 14 else if(m == 0) 15 { 16 double x = (double)b * (-1) / (2 * a); 17 printf("%.2lf", x); 18 } 19 else 20 { 21 double x = ((double)b * (-1) - sqrt(m)) / (2 * a); 22 double y = ((double)b * (-1) + sqrt(m)) / (2 * a); 23 printf("%.2lf %.2lf", x, y); 24 } 25 cout << endl; 26 } 27 return 0; 28 }
其他做法
韦达定理得：x1＋x2=－b/a，x1*x2=c/a去求解x1-x2=sqrt((x1+x2)*(x1+x2)-4*x1*x2)，然后就可以求出x1,x2啦！还要记得保留两位小数哟！
