c语言答案_c语言答案图文
c语言答案由刀豆文库小编整理，希望给你工作、学习、生活带来方便，猜你可能喜欢“c语言答案图文”。
6-13
#include int main(){ char s1[80],s2[40];
int i=0,j=0;
printf(“input string1:”);
scanf(“%s”,s1);
printf(“input string2:”);
scanf(“%s”,s2);
while(s1[i]!=' ')
i++;
while(s2[j]!=' ')
s1[i++]=s2[j++];
s1[i]=' ';
printf(“nThe new string is:%sn”,s1);
return 0;}
6-14 #include int main(){ int i,resu;
char s1[100],s2[100];
printf(“input string1:”);
gets(s1);
printf(“ninput string2:”);
gets(s2);
i=0;
while((s1[i]==s2[i])&&(s1[i]!=' '))i++;
if(s1[i]==' ' && s2[i]==' ')
resu=0;
else
resu=s1[i]-s2[i];
printf(“nresult:%d.n”,resu);
return 0;}
6-15 #include #include int main(){ char s1[80],s2[80];
int i;
printf(“input s2:”);
scanf(“%s”,s2);
for(i=0;i
s1[i]=s2[i];
printf(“s1:%sn”,s1);
return 0;}
第7章用函数实现模块化程序设计170 7.1为什么要用函数170 7.2怎样定义函数172 7.2.1为什么要定义函数172 7.2.2定义函数的方法173 7.3调用函数174 7.3.1函数调用的形式174 7.3.2函数调用时的数据传递175 7.3.3函数调用的过程177 7.3.4函数的返回值178 7.4对被调用函数的声明和函数原型179 7.5函数的嵌套调用182 7.6函数的递归调用184 7.7数组作为函数参数192 7.7.1数组元素作函数实参193 7.7.2数组名作函数参数194 7.7.3多维数组名作函数参数197 7.8局部变量和全局变量199 7.8.1局部变量199 7.8.2全局变量200 7.9变量的存储方式和生存期204 7.9.1动态存储方式与静态存储方式204 7.9.2局部变量的存储类别205 7.9.3全局变量的存储类别208 7.9.4存储类别小结212 7.10关于变量的声明和定义214 7.11内部函数和外部函数215 7.11.1内部函数215 7.11.2外部函数215 习题218 7-1-1 #include int main(){int hcf(int,int);
int lcd(int,int,int);
int u,v,h,l;
scanf(“%d,%d”,&u,&v);
h=hcf(u,v);
printf(“H.C.F=%dn”,h);
l=lcd(u,v,h);
printf(“L.C.D=%dn”,l);
return 0;}
int hcf(int u,int v){int t,r;if(v>u)
{t=u;u=v;v=t;} while((r=u%v)!=0)
{u=v;
v=r;} return(v);}
int lcd(int u,int v,int h)
{
return(u*v/h);
}
7-1-2 #include int Hcf,Lcd;int main(){void hcf(int,int);
void lcd(int,int);
int u,v;
scanf(“%d,%d”,&u,&v);
hcf(u,v);
lcd(u,v);
printf(“H.C.F=%dn”,Hcf);
printf(“L.C.D=%dn”,Lcd);
return 0;}
void hcf(int u,int v){int t,r;if(v>u)
{t=u;u=v;v=t;} while((r=u%v)!=0)
{u=v;
v=r;
} Hcf=v;}
void lcd(int u,int v)
{
Lcd=u*v/Hcf;
}
7-2 #include #include float x1,x2,disc,p,q;int main(){void greater_than_zero(float,float);void equal_to_zero(float,float);void smaller_than_zero(float,float);float a,b,c;printf(“input a,b,c:”);scanf(“%f,%f,%f”,&a,&b,&c);printf(“equation: %5.2f*x*x+%5.2f*x+%5.2f=0n”,a,b,c);disc=b*b-4*a*c;printf(“root:n”);if(disc>0)
{
greater_than_zero(a,b);
printf(“x1=%fttx2=%fn”,x1,x2);
} else if(disc==0)
{equal_to_zero(a,b);
printf(“x1=%fttx2=%fn”,x1,x2);
} else
{smaller_than_zero(a,b);
printf(“x1=%f+%fitx2=%f-%fin”,p,q,p,q);
} return 0;}
void greater_than_zero(float a,float b){x1=(-b+sqrt(disc))/(2*a);
x2=(-b-sqrt(disc))/(2*a);}
void equal_to_zero(float a,float b){
x1=x2=(-b)/(2*a);}
void smaller_than_zero(float a,float b){
p=-b/(2*a);
q=sqrt(-disc)/(2*a);}
7-3 #include int main(){int prime(int);
int n;
printf(“input an integer:”);
scanf(“%d”,&n);
if(prime(n))
printf(“%d is a prime.n”,n);
else
printf(“%d is not a prime.n”,n);
return 0;}
int prime(int n)
{int flag=1,i;
for(i=2;i
if(n%i==0)
flag=0;
return(flag);
}
7-4 #include #define N 3 int array[N][N];int main(){ void convert(int array[][3]);int i,j;printf(“input array:n”);for(i=0;i
for(j=0;j
scanf(“%d”,&array[i][j]);printf(“noriginal array :n”);for(i=0;i
{for(j=0;j
printf(“%5d”,array[i][j]);
printf(“n”);
} convert(array);printf(“convert array:n”);for(i=0;i
{for(j=0;j
printf(“%5d”,array[i][j]);
printf(“n”);
} return 0;}
void convert(int array[][3]){int i,j,t;for(i=0;i
for(j=i+1;j
{t=array[i][j];
array[i][j]=array[j][i];
array[j][i]=t;
} }
#include #include int main(){void inverse(char str[]);char str[100];printf(“input string:”);scanf(“%s”,str);inverse(str);printf(“inverse string:%sn”,str);return 0;}
void inverse(char str[]){char t;
int i,j;
for(i=0,j=strlen(str);i
{t=str[i];
str[i]=str[j-1];
str[j-1]=t;
} }
7-6
#include int main(){void concatenate(char string1[],char string2[],char string[]);char s1[100],s2[100],s[100];printf(“input string1:”);scanf(“%s”,s1);printf(“input string2:”);scanf(“%s”,s2);concatenate(s1,s2,s);printf(“nThe new string is %sn”,s);return 0;}
void concatenate(char string1[],char string2[],char string[]){int i,j;for(i=0;string1[i]!=' ';i++)
string[i]=string1[i];for(j=0;string2[j]!=' ';j++)
string[i+j]=string2[j];string[i+j]=' ';}
7-7 #include int main(){void cpy(char [],char []);char str[80],c[80];printf(“input string:”);gets(str);cpy(str,c);printf(“The vowel letters are:%sn”,c);return 0;}
void cpy(char s[],char c[]){ int i,j;
for(i=0,j=0;s[i]!=' ';i++)
if(s[i]=='a'||s[i]=='A'||s[i]=='e'||s[i]=='E'||s[i]=='i'||
s[i]=='I'||s[i]=='o'||s[i]=='O'||s[i]=='u'||s[i]=='U')
{c[j]=s[i];
j++;
}
c[j]=' ';}
7-8 #include #include int main(){char str[80];void insert(char []);printf(“input four digits:”);scanf(“%s”,str);insert(str);return 0;}
void insert(char str[]){int i;for(i=strlen(str);i>0;i--)
{str[2*i]=str[i];
str[2*i-1]=' ';
} printf(“output:n%sn”,str);} 7-9 #include int letter,digit,space,others;int main(){void count(char []);char text[80];printf(“input string:n”);gets(text);printf(“string:”);puts(text);letter=0;digit=0;space=0;others=0;count(text);
printf(“nletter:%dndigit:%dnspace:%dnothers:%dn”,letter,digit,space,others);return 0;}
void count(char str[]){int i;for(i=0;str[i]!=' ';i++)if((str[i]>='a'&& str[i]='A' && str[i]
letter++;else if(str[i]>='0' && str [i]
digit++;else if(str[i]==32)
space++;else
others++;} 7-10 #include #include int main(){int alphabetic(char);int longest(char []);int i;char line[100];printf(“input one line:n”);gets(line);printf(“The longest word is :”);for(i=longest(line);alphabetic(line[i]);i++)
printf(“%c”,line[i]);printf(“n”);return 0;}
int alphabetic(char c){if((c>='a' && c='A'&&c
return(1);else
return(0);}
int longest(char string[]){int len=0,i,length=0,flag=1,place=0,point;for(i=0;i
if(alphabetic(string[i]))
if(flag)
{point=i;
flag=0;
}
else
len++;
else
{flag=1;
if(len>=length)
{length=len;place=point;len=0;}
} return(place);}
7-11 #include #include #define N 10 char str[N];int main(){void sort(char []);int i,flag;for(flag=1;flag==1;)
{printf(“input string:n”);
scanf(“%s”,&str);
if(strlen(str)>N)
printf(“string too long,input again!”);
else
flag=0;
} sort(str);printf(“string sorted:n”);for(i=0;i
printf(“%c”,str[i]);printf(“n”);return 0;}
void sort(char str[]){int i,j;char t;for(j=1;j
for(i=0;(i
if(str[i]>str[i+1])
{t=str[i];
str[i]=str[i+1];
str[i+1]=t;
} }
7-12 #include #include int main(){float solut(float a,float b,float c,float d);float a,b,c,d;printf(“input a,b,c,d:”);scanf(“%f,%f,%f,%f”,&a,&b,&c,&d);printf(“x=%10.7fn”,solut(a,b,c,d));return 0;}
float solut(float a,float b,float c,float d){float x=1,x0,f,f1;do
{x0=x;
f=((a*x0+b)*x0+c)*x0+d;
f1=(3*a*x0+2*b)*x0+c;
x=x0-f/f1;
} while(fabs(x-x0)>=1e-3);return(x);}
7-13 #include #define N 10 #define M 5 float score[N][M];float a_stu[N],a_cour[M];int r,c;
int main(){ int i,j;
float h;
float s_var(void);
float highest();
void input_stu(void);
void aver_stu(void);
void aver_cour(void);
input_stu();
aver_stu();
aver_cour();
printf(“n NO.cour1
cour2
cour3
cour4 avern”);
for(i=0;i
{printf(“n NO %2d ”,i+1);
for(j=0;j
printf(“%8.2f”,score[i][j]);
printf(“%8.2fn”,a_stu[i]);
}
printf(“naverage:”);
for(j=0;j
printf(“%8.2f”,a_cour[j]);
printf(“n”);
h=highest();
printf(“highest:%7.2f
NO.%2d
course %2dn”,h,r,c);
printf(“variance %8.2fn”,s_var());
return 0;
cour5
}
void input_stu(void){int i,j;
for(i=0;i
{printf(“ninput score of student%2d:n”,i+1);
for(j=0;j
scanf(“%f”,&score[i][j]);
} }
void aver_stu(void){int i,j;
float s;
for(i=0;i
{for(j=0,s=0;j
s+=score[i][j];
a_stu[i]=s/5.0;
} } void aver_cour(void){int i,j;
float s;
for(j=0;j
{s=0;
for(i=0;i
s+=score[i][j];
a_cour[j]=s/(float)N;
} }
float highest(){float high;
int i,j;
high=score[0][0];
for(i=0;i
for(j=0;j
if(score[i][j]>high)
{high=score[i][j];r=i+1;c=j+1;}
return(high);}
float s_var(void){int i;
float sumx,sumxn;
sumx=0.0;
sumxn=0.0;
for(i=0;i
{sumx+=a_stu[i]*a_stu[i];
sumxn+=a_stu[i];
}
return(sumx/N-(sumxn/N)*(sumxn/N));}
7-*14 #include #define N 10 #define M 5 float score[N][M];float a_stu[N],a_cour[M];int r,c;
int main(){ int i,j;
float h;
float s_var(void);
float highest();
void input_stu(void);
void aver_stu(void);
void aver_cour(void);
input_stu();
aver_stu();
aver_cour();
printf(“n NO.cour1 avern”);
for(i=0;i
{printf(“n NO %2d ”,i+1);
for(j=0;j
printf(“%8.2f”,score[i][j]);
printf(“%8.2fn”,a_stu[i]);
}
cour2
cour3 cour4
cour5
printf(“naverage:”);
for(j=0;j
printf(“%8.2f”,a_cour[j]);
printf(“n”);
h=highest();
printf(“highest:%7.2f
NO.%2d
course %2dn”,h,r,c);
printf(“variance %8.2fn”,s_var());
return 0;}
void input_stu(void){int i,j;
for(i=0;i
{printf(“ninput score of student%2d:n”,i+1);
for(j=0;j
scanf(“%f”,&score[i][j]);
} }
void aver_stu(void){int i,j;
float s;
for(i=0;i
{for(j=0,s=0;j
s+=score[i][j];
a_stu[i]=s/5.0;
} }
void aver_cour(void){int i,j;
float s;
for(j=0;j
{s=0;
for(i=0;i
s+=score[i][j];
a_cour[j]=s/(float)N;
} }
float highest(){float high;
int i,j;
high=score[0][0];
for(i=0;i
for(j=0;j
if(score[i][j]>high)
{high=score[i][j];r=i+1;c=j+1;}
return(high);}
float s_var(void){int i;
float sumx,sumxn;
sumx=0.0;
sumxn=0.0;
for(i=0;i
{sumx+=a_stu[i]*a_stu[i];
sumxn+=a_stu[i];
}
return(sumx/N-(sumxn/N)*(sumxn/N));} 7-15 #include #include #define N 10 int main()
{void input(int [],char name[][8]);
void sort(int [],char name[][8]);void search(int ,int [],char name[][8]);int num[N],number,flag=1,c;
char name[N][8];
input(num,name);
sort(num,name);
while(flag==1)
{printf(“ninput number to look for:”);
scanf(“%d”,&number);
search(number,num,name);
printf(“continue ot not(Y/N)?”);
getchar();
c=getchar();
if(c=='N'||c=='n')
flag=0;
} return 0;
}
void input(int num[],char name[N][8]){int i;
for(i=0;i
{printf(“input NO.: ”);
scanf(“%d”,&num[i]);
printf(“input name: ”);
getchar();
gets(name[i]);
} }
void sort(int num[],char name[N][8]){ int i,j,min,templ;
char temp2[8];
for(i=0;i
{min=i;
for(j=i;j
if(num[min]>num[j])min=j;
templ=num[i];
strcpy(temp2,name[i]);
num[i]=num[min];
strcpy(name[i],name[min]);
num[min]=templ;
strcpy(name[min],temp2);
}
printf(“n result:n”);
for(i=0;i
printf(“n %5d%10s”,num[i],name[i]);}
void search(int n,int num[],char name[N][8])
{int top,bott,mid,loca,sign;
top=0;
bott=N-1;
loca=0;
sign=1;
if((nnum[N-1]))loca=-1;
while((sign==1)&&(top
if(n==num[mid])
{loca=mid;
printf(“NO.%d , his name is %s.n”,n,name[loca]);
sign=-1;
} else if(n
bott=mid-1;else
top=mid+1;}
if(sign==1 || loca==-1)
printf(“%d not been found.n”,n);
}
7-16 #include #define MAX 1000 int main(){ int htoi(char s[]);
int c,i,flag,flag1;
char t[MAX];
i=0;
flag=0;
flag1=1;
printf(“input a HEX number:”);
while((c=getchar())!=' ' && i
{if(c>='0' && c='a' && c='A' && c
{flag=1;
t[i++]=c;
}
else if(flag)
{t[i]=' ';
printf(“decimal number %dn”,htoi(t));
printf(“continue or not?”);
c=getchar();
if(c=='N'||c=='n')
flag1=0;
else
{flag=0;
i=0;
printf(“ninput a HEX number:”);
}
}
}
return 0;
}
int htoi(char s[])
{ int i,n;
n=0;
for(i=0;s[i]!=' ';i++)
{if(s[i]>='0'&& s[i]
n=n*16+s[i]-'0';
if(s[i]>='a' && s[i]
n=n*16+s[i]-'a'+10;
if(s[i]>='A' && s[i]
n=n*16+s[i]-'A'+10;
}
return(n);
}
7-17 #include int main(){ void convert(int n);
int number;
printf(“input an integer: ”);
scanf(“%d”,&number);
printf(“output: ”);
if(number
number=-number;
}
convert(number);
printf(“n”);
return 0;}
void convert(int n){ int i;
if((i=n/10)!=0)
convert(i);
putchar(n%10+'0');
putchar(32);
先输出一个‘-’号和空格 }
7-18 #include int main(){int sum_day(int month,int day);int leap(int year);int year,month,day,days;printf(“input date(year,month,day):”);scanf(“%d,%d,%d”,&year,&month,&day);printf(“%d/%d/%d ”,year,month,day);days=sum_day(month,day);
sum_day */
if(leap(year)&&month>=3)/* */
days=days+1;printf(“is the %dth day in this year.n”,days);return 0;}
/* 调用函数调用函数leap
int sum_day(int month,int day)/* 函数sum_day:计算日期 */
{int day_tab[13]={0,31,28,31,30,31,30,31,31,30,31,30,31};
int i;
for(i=1;i
return(day);} /* 函数leap:判断是否为闰年 */
int leap(int year){int leap;
leap=year%4==0&&year%100!=0||year%400==0;
return(leap);}
第8章善于利用指针220 8.1指针是什么220 8.2指针变量222 8.2.1使用指针变量的例子222 8.2.2怎样定义指针变量223 8.2.3怎样引用指针变量224 8.2.4指针变量作为函数参数226 8.3通过指针引用数组230 8.3.1数组元素的指针230 8.3.2在引用数组元素时指针的运算231 8.3.3通过指针引用数组元素233 8.3.4用数组名作函数参数237 8.3.5通过指针引用多维数组245 8.4通过指针引用字符串255 8.4.1字符串的引用方式 255 8.4.2字符指针作函数参数259 8.4.3使用字符指针变量和字符数组的比较263 8.5指向函数的指针266 8.5.1什么是函数指针266 8.5.2用函数指针变量调用函数266 8.5.3怎样定义和使用指向函数的指针变量268 8.5.4用指向函数的指针作函数参数270 8.6返回指针值的函数274 8.7指针数组和多重指针277 8.7.1什么是指针数组 277 8.7.2指向指针数据的指针280 8.7.3指针数组作main函数的形参282 8.8动态内存分配与指向它的指针变量285 8.8.1什么是内存的动态分配285 8.8.2怎样建立内存的动态分配285 8.8.3void指针类型 287 8.9有关指针的小结288 习题291 8-1 #include int main(){ void swap(int *p1,int *p2);int n1,n2,n3;int *p1,*p2,*p3;printf(“input three integer n1,n2,n3:”);scanf(“%d,%d,%d”,&n1,&n2,&n3);p1=&n1;p2=&n2;p3=&n3;if(n1>n2)swap(p1,p2);if(n1>n3)swap(p1,p3);if(n2>n3)swap(p2,p3);printf(“Now,the order is:%d,%d,%dn”,n1,n2,n3);return 0;} void swap(int *p1,int *p2)
{int p;
p=*p1;*p1=*p2;*p2=p;
}
#include #include int main(){void swap(char *,char *);char str1[20],str2[20],str3[20];printf(“input three line:n”);gets(str1);gets(str2);gets(str3);if(strcmp(str1,str2)>0)swap(str1,str2);if(strcmp(str1,str3)>0)swap(str1,str3);if(strcmp(str2,str3)>0)swap(str2,str3);printf(“Now,the order is:n”);printf(“%sn%sn%sn”,str1,str2,str3);return 0;}
void swap(char *p1,char *p2){char p[20];
strcpy(p,p1);strcpy(p1,p2);strcpy(p2,p);}
8-3 #include int main(){ void input(int *);
void max_min_value(int *);
void output(int *);
int number[10];
input(number);
max_min_value(number);
output(number);
return 0;}
void input(int *number)
{int i;
printf(“input 10 numbers:”);
for(i=0;i
scanf(“%d”,&number[i]);
}
void max_min_value(int *number)
{ int *max,*min,*p,temp;
max=min=number;
for(p=number+1;p
if(*p>*max)max=p;
else if(*p
temp=number[0];number[0]=*min;*min=temp;
if(max==number)max=min;
temp=number[9];number[9]=*max;*max=temp;
}
void output(int *number)
{int *p;
printf(“Now,they are:
”);
for(p=number;p
printf(“%d ”,*p);
printf(“n”);
}
8-4 #include int main()
{void move(int [20],int,int);
int number[20],n,m,i;printf(“how many numbers?”);scanf(“%d”,&n);printf(“input %d numbers:n”,n);for(i=0;i
scanf(“%d”,&number[i]);printf(“how many place you want move?”);scanf(“%d”,&m);move(number,n,m);printf(“Now,they are:n”);for(i=0;i
printf(“%d ”,number[i]);printf(“n”);return 0;}
void move(int array[20],int n,int m)
{int *p,array_end;
array_end=*(array+n-1);
for(p=array+n-1;p>array;p--)
*p=*(p-1);
*array=array_end;
m--;
if(m>0)move(array,n,m);
} 8-5 #include int main(){int i,k,m,n,num[50],*p;printf(“ninput number of person: n=”);scanf(“%d”,&n);p=num;for(i=0;i
*(p+i)=i+1;
i=0;
k=0;
m=0;
while(m
{if(*(p+i)!=0)k++;
if(k==3)
{*(p+i)=0;
k=0;
m++;
}
i++;
if(i==n)i=0;
} while(*p==0)p++;printf(“The last one is NO.%dn”,*p);return 0;}
8-6 #include int main(){int length(char *p);int len;char str[20];printf(“input string: ”);scanf(“%s”,str);len=length(str);printf(“The length of string is %d.n”,len);return 0;}
int length(char *p)
{int n;n=0;while(*p!=' ')
{n++;
p++;
} return(n);}
8-7 #include #include int main(){void copystr(char *,char *,int);
int m;char str1[20],str2[20];printf(“input string:”);gets(str1);printf(“which character that begin to copy?”);scanf(“%d”,&m);if(strlen(str1)
printf(“input error!”);else
{copystr(str1,str2,m);
printf(“result:%sn”,str2);
} return 0;}
void copystr(char *p1,char *p2,int m)
{int n;
