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#include #include #include #include #include using namespace std;typedef long long ll;const int N = 1e4+5;inline int read() { char c=getchar(); int x=0,f=1; while(c<'0' || c>'9') {if(c=='-')f=-1; c=getchar();} while(c>='0' && c<='9') {x=x*10+c-'0'; c=getchar();} return x*f;}int n, a[N], b[N], c[N];double f(double x) { double x2 = x*x, ans = a[1]*x2 + b[1]*x + c[1]; for(int i=2; i<=n; i++) ans = max(ans, a[i]*x2 + b[i]*x + c[i]); return ans;}void solve() { double l=0, r=1000; for(int i=0; i<100; i++) { double len = (r-l)/3, m1 = l+len, m2 = r-len; if(f(m1) < f(m2)) r = m2; else l = m1; } printf("%.4lf\n", f(l));}int main() { freopen("in", "r", stdin); int T = read(); while(T--) { n = read(); for(int i=1; i<=n; i++) a[i] = read(), b[i] = read(), c[i] = read(); solve(); }}
转载于:https://www.cnblogs.com/candy99/p/6764766.html