HUst 1360 Solve the integration（定积分模板）

题意：

就是给你一个函数，让你求他的定积分。

//训练前不知道kuangbin dalao还有之中模板，真的是长见识了，差点爆零，还好有A题，不过A题也都是坑

 

思路就是直接套模板

#include <cstdio>
#include <cstring>
#include <cmath>
double const eps=1e-6;

double F(double x)
{
    return 1.0/sqrt(1.0+x*x);
}



double simpson(double a,double b)
{
    double c = a + (b-a)/2;
    return (F(a)+4*F(c) + F(b)) * (b-a)/6;
}


double asr(double a,double b,double eps,double A)
{
    double c = a + (b-a)/2;
    double L = simpson(a,c),R = simpson(c,b);
    if(fabs(L + R - A) <= 15*eps)return L + R + (L + R - A)/15.0;
    return asr(a,c,eps/2,L) + asr(c,b,eps/2,R);
}


double asr(double a,double b,double eps)
{
    return asr(a,b,eps,simpson(a,b));
}

int main()
{
    double n;
    while(~scanf("%lf",&n))
    {
        printf("%.6f\n",asr(0,n,eps));
    }
    return 0;
}