《C语言程序设计》第二章例题源代码

【例2-1】
#include<stdio.h>
int main(void)
{
printf("Hello World!\n");
return 0;
}
【例2-2】
#include<stdio.h>
int main(void)
{
printf("Programming is fun.\n");
printf("And Programming in C is even more fun!\n");
return 0;
}
【例2-3】
#include<stdio.h>
int main(void)
{
int celsius,fahr;
fahr=100;
celsius=5*(fahr-32)/9;
printf("fahr=%d,celsius=%d\n",fahr,celsius);
return 0;
}
【例2-4】
#include<stdio.h>
int main(void)
{
double x,y;
printf("Enter x(x>=0):\n");
scanf("%lf",&x);
if(x<=15)
{
y=4*x/3;
}
else
{
y=2.5*x-10.5;
}
printf("y=f(%f)=%.2f\n",x,y);
return 0;
}
[例2-5]
#include<stdio.h>
#include<math.h>
int main(void)
{
int money,year;
double rate,sum;
printf("Enter money:");
scanf("%d",&money);
printf("Enter year:");
scanf("%d",&year);
printf("Enter rate:");
scanf("%lf",&rate);
sum=money*pow((1 rate),year);
printf("sum=%.2f\n",sum);
return 0;
}
[例2-6]
#include<stdio.h>
int main(void)
{
int fahr,lower,upper;
double celsius;
printf("Enter lower:");
scanf("%d",&lower);
printf("Enter upper:");
scanf("%d",&upper);
printf("fahr celsius\n");
for(fahr=lower;fahr<=upper;fahr )
{
celsius=(5.0/9.0)*(fahr-32);
printf(" %d %6.1f\n",fahr,celsius);
}
return 0;
}
[例2-7]
#include<stdio.h>
int main(void)
{
int i,n,sum;
printf("Enter n:");
scanf("%d",&n);
sum=0;
for(i=1;i<=n;i )
{
sum=sum i;
}
printf("Sum of numbers from 1 to %d is %d\n",n,sum);
return 0;
}
[例2-8]
#include<stdio.h>
int main(void)
{
int denominator,flag,i,n;
double item,sum;
printf("Enter n:");
scanf("%d",&n);
flag=1;
denominator=1;
sum=0;
for(i=1;i<=n;i )
{
item=flag*1.0/denominator;
sum=sum item;
flag=-flag;
denominator=denominator 2;
}
printf("sum=%f\n",sum);
return 0;
}
[例2-9]
#include<stdio.h>
int main(void)
{
int i,n;
double product;
printf("Enter n:");
scanf("%d",&n);
product=1;
for(i=1;i<=n;i )
{
product=product*i;
}
printf("product=%.0f\n",product);
return 0;
}
[例2-10-1]
#include<stdio.h>
#include<math.h>
int main(void)
{
int i,n;
double power;
printf("Enter n:");
scanf("%d",&n);
for(i=0;i<=n;i )
{
power=pow(2,i);
printf("pow(2,%d)=%.0f\n",i,power);
}
return 0;
}
[例2-10-2]
#include<stdio.h>
double fact(int n);
int main(void)
{
int i,n;
double result;
printf("Enter n:");
scanf("%d",&n);
for(i=0;i<=n;i )
{
result=fact(i);
printf("%d!=%.0f\n",i,result);
}
return 0;
}
double fact(int n)
{
int i;
double product;
product=1;
for(i=1;i<=n;i )
{
product=product*i;
}
return product;
}