C++求积分代码

基本上是靠定义来求的，而且代码也简明扼要，精度为1/1000；
如下：

#include"iostream"

#include"cstdlib"

#include"cmath"

#define N 1000

using namespace std;

double f(double x)

{

return x*x*x;

}

double intergrate(double(*fp)(double), double
a, double b)

{

fp = f;

int N = (b - a) * N;

double dx = (double)1/N;

double s = 0;

for (int i = 1; i <= N; i++)

{

s += f(a + dx)*dx;

a += dx;

}

return s;

}

int main()

{

cout << "f(x)=x^3" << endl;

cout << "f(x)在(0,1)的积分：" << intergrate(f, 0,
1);

system("pause");

return 0;

}

想要更改精度的话可以直接修改N的值