UVALive

#include<cstdio>#include<cstdlib>#include<cstring>#include<iostream>#include<cmath>#include<string>#include <bits/stdc++.h>using namespace std;typedef long long LL;const int N =1e5+10;const int inf = 0x3f3f3f3f;struct node{    double a, b, c;}p[N];int n;double get(double x){    double ans=0;    ans=p[0].a*x*x+p[0].b*x+p[0].c;    for(int i=1;i<n;i++) ans=max(ans,p[i].a*x*x+p[i].b*x+p[i].c);    return ans;}int main(){    int t;    scanf("%d", &t);    while(t--)    {        scanf("%d", &n);        for(int i=0;i<n;i++) scanf("%lf %lf %lf", &p[i].a, &p[i].b, &p[i].c);        double l=0, r=1000, ans;        for(int i=0;i<100;i++)        {            double x1=l+(r-l)/3, x2=(r-(r-l)/3);            double y1=get(x1), y2=get(x2);            if(y1<y2) ans=y1,r=x2;            else ans=y2,l=x1;        }        printf("%.4f\n",ans);    }    return 0;}