CodeForces 20B Equation 水题

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#include <cstdio>#include <cstring>#include <algorithm>#include <vector>#include <iostream>#include <map>#include <set>#include <math.h>using namespace std;#define inf 10000000#define ll __int64#define N 2005ll a,b,c;int main(){ll i, j;while(cin>>a>>b>>c) {double A = (double)a, B = (double)b, C = (double)c;if(a==0) {if(b==0) {if(c==0)puts("-1");else puts("0");continue;}puts("1");printf("%.10lf\n", (-C)/B);continue;}ll h = b*b-4*a*c;if(h<0){puts("0");continue;}if(h==0) {puts("1");printf("%.10lf\n",-(B/(2.0*A)));}else {puts("2");double H = sqrt((double)h);if((-B-H)/(2.0*A) > (-B+H)/(2.0*A))H *= -1;printf("%.10lf\n%.10lf\n", (-B-H)/(2.0*A), (-B+H)/(2.0*A));}}return 0;}