#include <cmath>  #include <cstdio> #define ACC 1000 float solve(float (*p)(float),float up,float down,int acc); float fun_exp(float x); float fun_qua(float x); void main(){ char selection; float up,down; while(printf("请选择被积函数:\n"),printf("1、exp(x)   2、x+1 \n"),scanf("%c",&selection),selection != '#'){ printf("请输入积分上下限: "); scanf("%f,%f",&up,&down); switch(selection){ case '1': printf("结果是: %4.4f\n",solve(fun_exp,up,down,ACC)); break; case '2': printf("结果是: %4.4f\n",solve(fun_qua,up,down,ACC)); break; } } } float solve(float (*p)(float),float up,float down,int acc){ float sum,base,area; area = 0; sum = 0; base = (up-down)/acc; for(int i=0; i area = base*((*p)(down+i*base)); sum+=area; } return sum; } float fun_exp(float x){ return exp(x); } float fun_qua(float x){ //一元二次方程 quadratics return x+1; }