华科周纯杰版c语言答案

第三章程序和流程控制

1.输入两个整数，输出较大者。

#include<>

void main()

{

int a,b;

int max=0;

printf("Please input two numbers:");

scanf("%d%d",&a,&b);

if(a<=b) max=b;

else max=a;

printf("The larger number is %d\n",max);

}

2.有3个整数a，b，c，由键盘输入，输出其中最大的数。

#include<>

void main()

{

int a,b,c,max;

printf("Please input three numbers:");

scanf("%d%d%d",&a,&b,&c);

if(a>b)

{

if(a>c) max=a;

else max=c;

}

else

{

if(b>c) max=b;

else max=c;

}

printf("The largest number is %d\n",temp);

}

3.从1累加到100，用while语句。

#include<>

#define N 100

void main()

{

int i=1,sum=0;

while(i<=N)

{

sum+=i;

i++;

}

printf("sum:%d\n",sum);

}

4.已知a1＝10，a2 ＝－3，an＝3an-1 ＋an-2 ，求{ a }的前十项。

#include<>

#define N 10

void main()

{

int a[20]={10,-3};

int i=0,m=0;

for(i=2;i

{

a[i]=3*a[i-1]+a[i-2];

}

m=N;

printf("The %d numbers are:\n",m);

for(i=0;i

{

printf("a[%d]=%d\n",i+1,a[i]);

}

}

5.输入一个自然数，判断它是奇数还是偶数。

#include<>

void main()

{

int a, temp;

printf("Please input a numbers:\n");

scanf("%d",&a);

temp=a%2;

if(temp==0)

printf("The number %d is an even!\n",a);

else

printf("The number %d is an odd number!\n",a);

}

6.已知a1 ＝8，an ＝an-1 ＋bn ，b1 ＝1，bn ＝bn-1 ＋3，求{ a }前10项之和。 #include<>

#define N 10

void main()

{

int a[N]={8},b[N]={1},i,sum=0;

for(i=1;i

{

b[i]=b[i-1]+3;

}

for(i=1;i

{

a[i]=a[i-1]+b[i];

}

for(i=0;i

{

sum+=a[i];

}

printf("The sum is:%d\n",sum);

}

7.有一个函数写一程序，输入x，输出Y的值。

#include<>

void main()

{

float x,y;

printf("Please input a float number x=:");

scanf("%f",&x);

printf("x=%f",x);

if(x<1)

y=x;

else if(x>=10)

y=3*x-11;

else

y=2*x-1;

printf("The value of y is:%.3f\n",y);

}

8.给一个不多于5位的的正整数，要求：求出它是几位数，分别打印出每一位数字，最后按照逆序打印各位数字，例如原数为321，应输出为123。

#include<>

#define N 99999

#define M 5

void main()

{

int i,j,k,m,b[M];

long int a,temp;

printf("Please input a number:\n");

scanf("%ld",&a);

if(a<0||a>N)

printf("Error in input data!!!\n");

else

{

temp=a;

for(i=0;temp!=0;i++)

{

temp=temp/10;

}

m=i;

printf("The number a=%ld have %d single numbers\n",a,m);

temp=a;

for(j=0;j

{

b[j]=temp%10;

temp=temp/10;

}

printf("The origal numbers are:\n");

for(k=m-1;k!=-1;k--)

{

printf("%d",b[k]);

}

printf("\n");

printf("every letter is:");

for(j=m-1;j>=0;j--)

printf("%d\t",b[j]);

printf("\n");

printf("The inverted numbers are:\n");

for(j=0;j

{

printf("%d",b[j]);

}

printf("\n");

}

}

9．编写一猜数游戏程序，随机产生某个整数，从键盘反复输入整数进行猜数，当未猜中时，提示输入过大或过小.猜中时，指出猜的次数.最多允许猜20次.

#include<>

#include<>

#include<>

#define N 10

void main()

{

int a,b,i;

randomize();

a=random(N);

printf("Please input number you guess:\n");

for(i=0;i<20;i++)

{

scanf("%d",&b);

if(b==a)

{

printf("Congratulation!!\nYour guessed number is right!\n");

printf("The time(s) you have guessed is %d",i+1);

break;

}

else if(b>a)

printf("Your number is too big!!\n");

else

printf("Your number is too small!!\n");

}

printf("\n");

}

10.计算1－999中能被3整除，且至少有一位数字是5的所有整数。

#include<>

#define N 999

void main()

{

int i,b,c,d;

printf("The numbers are:\n");

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

{

if(i%3)

{

b=i/100;

c=(i-100*b)/10;

d=i%10;

if(b==5||c==5||d==5)

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

}

}

}

11.输入两个整数，求它们的最大公约数和最小公倍数。

#include ""

void main()

{

int a,b,c,d;

int comYueShu;

int comBeishu;

printf("please input two number!");

scanf("%d %d",&a,&b);

c=a;

d=b;

int r;

入一个整数，求它包含又多少个2的因子。（例如，8含有3个2的因子，10含有一个2的因子，15不含有2的因子。）

#include ""

void main()

{

int a=0;

int integerGene=0;

printf("input a number!\n");

scanf("%d",&a);

while(a%2==0)

{

integerGene++;

a/=2;

}

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

}

13.计算1！，2！，3！…10！

#include<>

#define N 10

void main()

{

int i;

long int a=1;

printf("The outcome are:\n");

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

{

a*=i;

printf("The result of %d! is %ld\n",i,a);

}

}

14.猴子吃桃问题：第一天吃掉总数的一半多一个，第二天又将剩下的桃子吃掉一半多一个，以后每天吃掉前一天剩下的一半多一个，到第十天准备吃的时候见只剩下一个桃子，求第一天开始吃的时候桃子的总数。

#include<>

#define N 10

void main()

{

int i,x[10];

x[9]=1;

for(i=9;i>=1;i--)

x[i-1]=2*(x[i]+1);

printf("The total numbers in the first day are:%d\n",x[0]);

}

15.输入圆锥体的底半径r和高h，计算出圆锥体的体积并输出

#include<>

#define PI

void main()

{

float r,h,v;

printf("Please input the radius and the height:\n");

scanf("%f%f",&r,&h);

v=PI*r*r*h/3;

printf("The volume of is %.6f\n",v);

16题

#include ""

void main()

{

int a,n;

long tmp,SUM=0;

do

{

printf("\nPlease input the number a=");

scanf("%d",&a);

}while(!(a>=0 && a<=9));

printf("\nPlease input the number,it's value is not too big n=");

scanf("%d",&n);

tmp = a;

while(n--)

{

SUM += tmp;

tmp = tmp * 10 + a;

}

printf("\na+aa+aaa+...=%ld(a= %d)\n",SUM,a);

}

#include ""

void main()

{

unsigned char week[7][20]={"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","satur day"};

unsigned char weekday;

do

{

printf("\nPlease input the weeday(0 =

scanf("%d",&weekday);

}while(!(weekday >= 0 && weekday <= 6));

printf("\n%d correspoind to %s\n",weekday,week[weekday]);

}

18题

#include ""

#include ""

void main()

{

float x,y;

float Result;

int i = 1;

printf("\nPlease input the value x =");

scanf("%f",&x);

Result = ;

y = x;

do

{

Result += y;

y = (y*x)/(i + 1);

i++;

}while(y > 1e-6);

printf("\nThe natural constant e, it's %f pow = %f",x,Result); }

19题

#include ""

#include ""

void main()

{

float a;

float x1,x2;

printf("\nPlease input the number a=");

scanf("%f",&a);

x1 = x2 = a/2;

do

{

x1=x2;

x2=(x1+(a/x1))/2;

}while(fabs(x2 - x1) > 1e-5);

printf("\nInput a namber %f,It's sqrt = %f",a,x2); }

第5章课后编程习题参考答案

2.已有一个已排好序的数组，现在输入一个数，要求按照原来排序的规则将它插入数组中。

#include<>

#define N 7

void main()

{

int a[N]={1,5,16,45,87,120};

int n,i,j,temp1,temp2,end;

printf("please enter a number:\n");

scanf("%d",&n);

end=a[N-2];

if(n>end)

a[N-1]=n;

else

{

for(i=0;i

{

if(n

{

for(j=N-1;j>i+1;j--)

{

a[j]=a[j-1];

}

a[i]=n;

break;

}

}

}

printf("put out the new array:\n");

for(i=0;i

printf("%4d",a[i]);

}

3.打印"魔方阵"，所谓魔方阵是指这样的方阵，它的每一行，每一列和对角线之和均相等。例如，三阶魔方阵为：

8 1 6

3 5 7

4 9 2

#include<>

void main()

{

int a[16][16];

int n,i,j,k;

do

{

printf("enter a number n(1~15):\n");

scanf("%d",&n);

}while(!((n>0)&&(n<=15)&&(n%2==1)));

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

for(j=1;j<=n;j++)

a[i][j]=0;

j=n/2+1;

a[1][j]=1;

for(k=2;k<=n*n;k++)

{

i=i-1;

j=j+1;

if((i<1)&&(j>n))

{

i=i+2;

j=j-1;

}

else

{

if(i<1) i=n;

if(j>n) j=1;

}

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

a[i][j]=k;

else

{

i=i+2;

j=j-1;

a[i][j]=k;

}

}

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

{

for(j=1;j<=n;j++)

printf("%4d",a[i][j]);

printf("\n");

}

}

}

4，有一篇文章，共有3行文字，每行有80个字符，要求分别统计出其中英文大写字母，小写字母，数字，空格以及其它字符的个数。

#include<>

#include <>

void main()

{

char s[3][80];

int i,j,up,low,num,spa,oth;

up=low=num=spa=oth=0;

for(i=0;i<3;i++)

{

printf("enter the %d line:\n",i+1);

gets(s[i]);

for(j=0;j<80&&s[i][j]!='\0';j++)

if(s[i][j]>='A'&&s[i][j]<='Z')

up++;

else if(s[i][j]>='a'&&s[i][j]<='z')

low++;

else if(s[i][j]>='0'&&s[i][j]<='9')

num++;

else if(s[i][j]==' ')

spa++;

else

oth++;

}

printf("up=%d\n",up);

printf("low=%d\n",low);

printf("num=%d\n",num);

printf("spa=%d\n",spa);

printf("oth=%d\n",oth);

}

5.编写一个程序，将两个字符串连起来，不要用strcat函数。

#include<>

#include <>

void main()

{

char s1[100],s2[100];

gets(s1);