c語言程序設(shè)計答案第4章習(xí)題參

C語言程序設(shè)計第四章課后習(xí)題答案

1、不是一個合法語句，會導(dǎo)致編譯無法通過

2、是，無法執(zhí)行循環(huán)結(jié)構(gòu)中的指令。

3、是，會進入死循環(huán)

4、20次

5、無窮多次

6、無窮多次

7、是，會進入死循環(huán)

8、是，會進入死循環(huán)

9、執(zhí)行50次

10、0次

11、#include<stdio.h>intmain()

{

inti,k,sign;

doublen,d,sa=0,sb=0,eps,e=1e-8;

eps=e/16.0;sign=1;

n=5;

for(i=0,d=1;d>eps;i++)

{

k=2*i+1;

d=1.0/(n*k);sa+=sign*d;n*=25;

sign*=-1;

}

eps=e/4.0;n=239;

sign=1;

for(i=0,d=1;d>eps;i++)

{

k=2*i+1;

d=1.0/(n*k);sb+=d*sign;

n=n*239*239;sign*=-1;

}

printf("%.8f\n",16*sa-4*sb);return0;

}

12、#include<stdio.h>intmain()

{

inti,k,sign;

doublen,d,sa=0,sb=0,eps,e=1e-8;

eps=e/16.0;sign=1;

n=5;

i=0;

d=1;

while(d>eps)

{

k=2*i+1;

d=1.0/(n*k);sa+=sign*d;n*=25;

sign*=-1;i++;

}

d=1;

eps=e/4.0;

n=239;

sign=1;

i=0;

while(d>eps)

{

k=2*i+1;

d=1.0/(n*k);sb+=d*sign;

n=n*239*239;sign*=-1;

i++;

}

printf("%.8f\n",16*sa-4*sb);return0;

}

13、#include<stdio.h>intmain()

{

intcount=0;

for(inti=2;i<1000;++i)

{

intflag=0;

for(intj=2;j<=i/2;++j)

{

if(i%j==0)

{

flag++;break;

}

}

if(flag==0)

{

printf("%d",i);count++;

if(count%10==0)

{

printf("\n");

}

}

}

}

14、#include<stdio.h>intmain()

{

charT;intm,n;

scanf("<%c><%d><%d>",&T,&m,&n);if(T=='F')

{

doublel,r;

l=((double)m-32)*5/9;

r=((double)n-32)*5/9;printf("%3d%3d",m,n);

printf("%3d.%.0lf%3d.%.0lf\n",(int)l,(l-(int)l)*10,(int)r,(r-(int)r)*10);

}

else

{

doublel,r;

l=9*(double)m/5+32;

r=9*(double)n/5+32;printf("%3d%3d",m,n);

printf("%3d.%.0lf%3d.%.0lf\n",(int)l,(l-(int)l)*10,(int)r,(r-(int)r)*10);

}

}

15、#include<stdio.h>intmain()

{

for(inti=1;i<10;i++)

{

for(intj=1;j<i+1;j++)

{

printf("%d*%d=%d",i,j,i*j);

}

printf("\n");

}

}

16、

#include<stdio.h>

constdoublet=0.621388;intmain()

{

printf("kmmile kmmile\n");for(inti=1;i<16;i++)

{

printf("%-2d%.4lf %d%.4lf\n",i,(double)i*t,i*5+15,(double)(i*5+15)*t);

}

}

17、#include<stdio.h>intrun(intm)

{

if(m%4!=0||(m%100==0&&m%400!=0))

return0;

else

return1;

}

intyear[2]={365,366};

intmonth[2][13]={0,31,28,31,30,31,30,31,31,30,31,30,31,0,31,29,31,30,31,30,31,31,30,31,30,31};

intmain(void)

{

inty,m,d,i,ans,n;scanf("%d%d%d%d%d",&y,&m,&d,&ans,&n);ans-=n+1;ans%=7;ans++;

if(n<d)

printf("%d%d%d%d",y,m,d,ans);

else

{

n-=d;d=0;

m--;

while(m>0)

if(n>=month[run(y)][m])

n-=month[run(y)][m],m--;

else

break;

if(m!=0)

printf("%d%d%d%d",y,m,month[run(y)][m]-n,ans);

else

{

y--;

while(n>=year[run(y)])

{

n-=year[run(y)];y--;

}m=12;

while(n>=month[run(y)][m])

{

n-=month[run(y)][m];m--;

}

d=month[run(y)][m]-n;

printf("%d%d%d%d",y,m,d,ans);

}

}

return0;

}

18、#include<stdio.h>intrun(intm)

{

if(m%4!=0||(m%100==0&&m%400!=0))

return0;

else

return1;

}

intyear[2]={365,366};

intmonth[2][13]={0,31,28,31,30,31,30,31,31,30,31,30,31,0,31,29,31,30,31,30,31,31,30,31,30,31};

intmain(void)

{

inty,m,d,i,ans=5;

scanf("%d-%d-%d",&y,&m,&d);if(y>=2000)

{

for(i=2000;i<y;i++)ans+=year[run(i)],ans%=7;

for(i=1;i<m;i++)

ans+=month[run(y)][i],ans%=7;ans+=d-1,ans%=7;printf("%d\n",ans+1);

}

else

{

ans-=month[run(y)][m]-d+1,ans%=7;for(i=m+1;i<=12;i++)

ans-=month[run(y)][i],ans%=7;for(i=y+1;i<2000;i++)

ans+=year[run(i)],ans%=7;printf("%d\n",ans+1);

}

return0;

}

19、

#include<stdio.h>inta[105];

intmain()

{

inti,j,n,ans=0;scanf("%d",&n);for(i=0;i<n;i++)

{

scanf("%d",&a[i]);for(j=0;j<i;j++)if(a[j]>a[i])

ans++;

}

printf("%d\n",ans);return0;

}

20、

#include<stdio.h>intmain()

{

inti,s,t,mid,beg,end,bj=0,t0;scanf("%d%d",&s,&t0);

for(t=t0;t>=2;t--)

if(s%t==0)

{

mid=s/t;beg=mid-t+1;

if(beg<0||beg%2==0)continue;

end=mid+t-1;bj=1;printf("%d=",s);

for(i=beg;i<end;i+=2)printf("%d+",i);

printf("%d\n",i);

}

if(bj==0)

printf("NONE\n");return0;

}

21、

#include<stdio.h>intmain()

{

inti,n;

longlongans=1;scanf("%d",&n);for(i=2;i<=n;i++)

{

ans*=i;while(ans%10==0)

ans/=10;

ans%=1600;//因為1600=100*16同學(xué)們可以想想為什么

}

printf("%02lld\n",ans%100);return0;

}

22、

#include<stdio.h>#include<math.h>intmain()

{

intm;

doublex,ans;while(~scanf("%lf%d",&x,&m))

{

ans=0;

doubletemp=x;

doublei=2.0,x1=-x*x;while(fabs(temp)>=pow(0.1,m))

{

ans+=temp;temp*=x1;temp/=i*(i+1);i+=2.0;

}

printf("%.12lf\n",ans);

}

}

23、

#include<stdio.h>intmain()

{

inti,n;scanf("%d",&n);if(n>0)

for(i=0;i<=n;i++)

printf("%d\n",i);

else

for(i=0;i>=n;i--)

printf("%d\n",i);

return0;

}

24、

#include<stdio.h>#include<string.h>intmain()

{

inti,ans=0,l;chars[100];scanf("%s",s);l=strlen(s);for(i=0;i<l;i++)

ans+=s[i]-'0';

printf("%d\n",ans);return0;

}

25、

#include<stdio.h>#include<math.h>intmain()

{

inti=1,m;

doublex,tmp,err,ans=1.0;scanf("%lf%d",&x,&m);x*=x;

tmp=1.0;err=pow(0.1,m);while(tmp>=err)

{

if(i%2==0)

ans+=tmp;

else

ans-=tmp;tmp*=x;tmp/=(double)((2*i)*(2*i-1));i++;

}

printf("%.*lf\n",m,ans);return0;

}

26、

#include<stdio.h>#include<string.h>chara[5],b[5],c[105];intmain()

{

inti,l;scanf("%s%s%s",a,b,c);l=strlen(c);for(i=0;i<l;i++)

if(c[i]==a[0])

c[i]=b[0];

printf("%s\n",c);return0;

}

27、

#include<stdio.h>

chars[150005],ans[150005];intmain()

{

inti,j=0,l=0,bj=0;while(~scanf("%c",&s[l++]))//Ctrl+z結(jié)束輸入

;

for(i=l-1;i>-1;i--)

{

if(bj==0)

{

if(s[i]=='\n')

bj=2;

elseif(s[i]=='')bj=1;ans[j++]=s[i];

}

elseif(bj>0)

{

if(s[i]=='\n')

bj=2,ans[j++]=s[i];

elseif(s[i]!='')

bj=0,ans[j++]=s[