#include<stdio.h>
double f(double x);
double sab(double a,double b,int n)
{double h,result,x1,x2,x3=0,t;int k;h=(b-a)/n;x1=f(a);x2=f(b);for(k=1;k<=n-1;k++){t=a+k*h;x3=x3+f(t);}return h*(x1+x2)/2+h*x3;
}

#include<stdio.h>
#include<math.h>
#include"sab.h"
double f(double x)
{double result;result=x*x*exp(x);return result;
}
main()
{double a,b,result;int n;printf("please input double a,b and integer n:");scanf("%lf%lf%d",&a,&b,&n);result=sab(a,b,n);printf("sab(%lf,%lf,%d)=%f",a,b,n,result);return 0;
} 

#include<stdio.h>
#include"sab.h"
double f(double x)
{double result;result=1/(25+x*x);return result;
}
main()
{double a,b,result;int n;printf("please input double a,b and integer n:");scanf("%lf%lf%d",&a,&b,&n);result=sab(a,b,n);printf("sab(%f,%f,%d)=%f",a,b,n,result);return 0;
}

#include<stdio.h>
int Ack(int n,int x,int y)
{int a;
if(n==0)a=a+1;
if(n==1&&y==0)    a=x;
if(n==2&&y==0)    a=0;
if(n==3&&y==0)    a=1;
if(n>=4&&y==0)    a=2;
if(n!=0&&y!=0)a=Ack(n-1,Ack(n,x,y-1),x);return a;
}
main()
{int n,x,y,result;printf("请输入n,x,y:");scanf("%d,%d,%d",&n,&x,&y);if(n<0||x<0||y<0)printf(" error!please input again!");result=Ack(n,x,y);printf("Ack(%d,%d,%d)=%d\n",n,x,y,result);
}

#include<stdio.h>
long getpower(int x,int y)
{if(y==1)return x;elsereturn x*getpower(x,y-1);
}
main()
{int num,power;long answer;printf("输入一个数");scanf("%d",&num);printf("输入幂次方");scanf("%d",&power); answer=getpower(num,power);printf("结果是:%ld\n",answer);
}

#include<stdio.h>
int age(int n)
{int c;if(n==1)c=10;elsereturn age(n-1)+2;return c;
}
main()
{int n=5;printf("%d",age(n));

#include<stdio.h>
Acm(int m,int n)
{if (m==0)    return n+1;if (n==0)return  Acm(m-1,1);if(n>0&&m>0)return Acm(m-1,Acm(m,n-1));
}
int main()
{int m,n,x,y;printf("please input two integers m,n:");scanf("%d%d",&m,&n);printf("please input two integers x,y:");scanf("%d%d",&x,&y);printf("Acm(%d，%d)=%d\n",m,n,Acm(m,n));printf("Acm(%d，%d)=%d",x,y,Acm(x,y));
}