他算出來了啊
#include <bits/stdc++.h>
using namespace std;
int main(void){
int a, b, c;
int x1, x2;
cin >> a >> b >> c;
if( (b^2 - (4*a*c)) > 0){
x1 = ((-b + sqrt(b^2-4 *a *c)) / (2*a)) ;
x2 = ((-b - sqrt(b^2-4 *a *c)) / (2*a)) ;
cout <<"x1="<<x1 <<"x2="<< x2 ;
}else if ( (b^2 - (4*a*c)) == 0){
x1 = ((-b + sqrt(b^2-4 *a *c)) / (2*a)) ;
x2 = ((-b - sqrt(b^2-4 *a *c)) / (2*a)) ;
cout <<"Two same roots x=" <<x1 ;
}else if ( (b^2 - (4 *a *c)) < 0){
cout << "No real roots";
}
}