作业 1 熟悉C语言编程环境 第二章

#include<stdio.h>
int main(void)
{
   printf("Hello World");

   return 0;

}

　　

　　

#include<stdio.h>
int main(void)
{
	printf("Programming is fun.\n");
	printf("And programming in C is even more fun!\n");

	return 0;

}

　　

#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;

}

　　

#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;
}

　　

#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;

}

　　

#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;

}

　　

#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;

}

　　

#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;
}

　　

#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;

}

　　

 

#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;

}

　　

#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;
}