c语言课后答案.doc

第二章
1.
#include <>
void main()
{
printf("Programming in C is fun!\n");
}
2.
#include <>
void main()
{
printf("+---+---+\n");
printf("| | |\n");
printf("| | |\n");
printf("+---+---+\n");
}
3.
#include <>
void main()
{
int f;
float c;
f=150;
c=5.*(f-32)/9.;
printf("f=%d,c=%.2f\n",f,c);
}
4.
#include <>
void main()
{
int a,b;
scanf("%d%d",&a,&b);
printf("%d+%d=%d\n",a,b,a+b);
printf("%d-%d=%d\n",a,b,a-b);
}
5.
#include<>
#include<>
void main()
{
float x,y;
scanf("%f",&x);
if(x<0)
y=x*x+2*x+1./x;
else
y=sqrt(x);
printf("x=%.3f,y=%.3f\n",x,y);
}
6.
#include<>
void main()
{
float x;
int y;
scanf("%f",&x);
if(x>0)
y=1;
else if(x==0)
y=0;
else
y=-1;
printf("x=%.3f,y=%d\n",x,y);
}
7.
#include<> /*(书上公式有误)*/
#include<>
void main()
{
float rate,accrual;
int money,year;
printf("money year rate=");
scanf("%d%d%f",&money,&year,&rate);
accrual=money*pow(1+rate,year)-money;
printf("accrual=%.2f\n",accrual);
}
8.
#include<>
void main()
{
int f;
float c;
printf(" f c\n");
for(f=10;f<=20;f++){
c=5.*(f-32)/9.;
printf("%3d%\n",f,c);
}
}
9.
#include<>
void main()
{
int s,i;
s=0;
for(i=10;i<=20;i++)
s=s+i;
printf("10+11+...+20=%d\n",s);
}
10.
#include<>
void main()
{
int i;
float s;
s=0;
for(i=5;i<=15;i++)
s=s+1./i;
printf("1/5+1/6+...+1/15=%f\n",s);
}
11.
#include<>
void main()
{
int i,n,flag;
float s,item;
s=0;
flag=1;
printf("n=");
scanf("%d",&n);
for(i=1;i<=n;i++){
item=flag*/(3*i-2);
s=s+item;
flag=-flag;
}
printf("s=%f\n",s);
}
12.
#include<>
double fact(int);
void main()
{
int i,m,n;
double f1,f2;
f1=1;f2=1;
printf("m n=");
scanf("%d%d",&m,&n);
for(i=1;i<=m;i++)
f1=f1*i;
for(i=1;i<=n;i++)
f2=f2*i;
printf("s=%f\n",f1+f2);
}
13.
#include<>
double mypow(doubl