C语言的学习要从基础开始,这里是100个经典的算法-1C语言的学习要从基础开始,这里是100个经典的算法
子长到第三个月后每个月又生一对兔子,假如兔子都不死,问每个月的兔子总数
为多少?
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程序分析:兔子的规律为数列1,1,2,3,5,8,13,21....
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程序源代码:
main()
{
long f1,f2;
int i;
f1=f2=1;
for(i=1;i<=20;i++)
{ printf("%12ld %12ld",f1,f2);
if(i%2==0) printf("/n");/*控制输出,每行四个*/
f1=f1+f2;/*前两个月加起来赋值给第三个月*/
f2=f1+f2;/*前两个月加起来赋值给第三个月*/
}
}
上题还可用一维数组处理,you try!
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程序分析:判断素数的方法:用一个数分别去除2到sqrt(这个数),如果能被整
除,则表明此数不是素数,反之是素数。
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程序源代码:
#include "math.h"
main()
{
int m,i,k,h=0,leap=1;
printf("/n");
for(m=101;m<=200;m++)
{ k=sqrt(m+1);
for(i=2;i<=k;i++)
if(m%i==0)
{leap=0;break;}
if(leap) {printf("%-4d",m);h++;
if(h%10==0)
printf("/n");
}
leap=1;
}
printf("/nThe total is %d",h);
}
数字立方和等于该数本身。例如:153是一个“水仙花数”,因为153=1的三次方
+5的三次方+3的三次方。
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程序分析:利用for循环控制100-999个数,每个数分解出个位,十位,百位。
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程序源代码:
main()
{
int i,j,k,n;
printf("'water flower'number is:");
for(n=100;n<1000;n++)
{
i=n/100;/*分解出百位*/
j=n/10%10;/*分解出十位*/
k=n%10;/*分解出个位*/
if(i*100+j*10+k==i*i*i+j*j*j+k*k*k)
{
printf("%-5d",n);
}
}
printf("/n");
}
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程序分析:对n进行分解质因数,应先找到一个最小的质数k,然后按下述步骤完
成:
(1)如果这个质数恰等于n,则说明分解质因数的过程已经结束,打印出即可。
(2)如果n<>k,但n能被k整除,则应打印出k的值,并用n除以k的商,作为新的正
整数你n,重复执行第一步。
(3)如果n不能被k整除,则用k+1作为k的值,重复执行第一步。
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程序源代码:
/* zheng int is divided yinshu*/
main()
{
int n,i;
printf("/nplease input a number:/n");
scanf("%d",&n);
printf("%d=",n);
for(i=2;i<=n;i++)
{
while(n!=i)
{
if(n%i==0)
{ printf("%d*",i);
n=n/i;
}
else
break;
}
}
printf("%d",n);
}
-89分之间的用B表示,60分以下的用C表示。
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程序分析:(a>b)?a:b这是条件运算符的基本例子。
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程序源代码:
main()
{
int score;
char grade;
printf("please input a score/n");
scanf("%d",&score);
grade=score>=90?'A'score>=60?'B':'C');
printf("%d belongs to %c",score,grade);
}
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程序分析:利用辗除法。
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程序源代码:
main()
{
int a,b,num1,num2,temp;
printf("please input two numbers:/n");
scanf("%d,%d",&num1,&num2);
if(num1 { temp=num1;
num1=num2;
num2=temp;
}
a=num1;b=num2;
while(b!=0)/*利用辗除法,直到b为0为止*/
{
temp=a%b;
a=b;
b=temp;
}
printf("gongyueshu:%d/n",a);
printf("gongbeishu:%d/n",num1*num2/a);
}
。
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程序源代码:
#include "stdio.h"
main()
{char c;
int letters=0,space=0,digit=0,others=0;
printf("please input some characters/n");
while((c=getchar())!='/n')
{
if(c>='a'&&c<='z'||c>='A'&&c<='Z')
letters++;
else if(c==' ')
space++;
else if(c>='0'&&c<='9')
digit++;
else
others++;
}
printf("all in all:char=%d space=%d digit=%d others=%
d/n",letters,space,digit,others);
}
2+22+222+2222+22222(此时共有5个数相加),几个数相加有键盘控制。
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程序分析:关键是计算出每一项的值。
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程序源代码:
main()
{
int a,n,count=1;
long int sn=0,tn=0;
printf("please input a and n/n");
scanf("%d,%d",&a,&n);
printf("a=%d,n=%d/n",a,n);
while(count<=n)
{
tn=tn+a;
sn=sn+tn;
a=a*10;
++count;
}
printf("a+aa+...=%ld/n",sn);
}
+3.编程找出1000以内的所有完数。
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程序源代码:
main()
{
static int k[10];
int i,j,n,s;
for(j=2;j<1000;j++)
{
n=-1;
s=j;
for(i=1;i {
if((j%i)==0)
{ n++;
s=s-i;
k[n]=i;
}
}
if(s==0)
{
printf("%d is a wanshu",j);
for(i=0;i printf("%d,",k);
printf("%d/n",k[n]);
}
}
}
求它在第10次落地时,共经过多少米?第10次反弹多高?
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程序源代码:
main()
{
float sn=100.0,hn=sn/2;
int n;
for(n=2;n<=10;n++)
{
sn=sn+2*hn;/*第n次落地时共经过的米数*/
hn=hn/2; /*第n次反跳高度*/
}
printf("the total of road is %f/n",sn);
printf("the tenth is %f meter/n",hn);
}
一半又多吃了一个,到第十天的时候发现还有一个.
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程序源代码:
/* 猴子吃桃问题 */
main()
{
int i,s,n=1;
for(i=1;i<10;i++)
{
s=(n+1)*2
n=s;
}
printf("第一天共摘了%d个桃/n",s);
}
迭代法求方程根
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/* 迭代法求一个数的平方根 */
#define Epsilon 1.0E-6 /*控制解的精度*/
#include
main()
{
float a,x0,x1;
printf("请输入要求的数:");
scanf("%f",&a);
x0=a/2;
x1=(x0+a/x0)/2;
while(fabs(x1-x0)>=Epsilon)
{
x0=x1;
x1=(x0+a/x0)/2;
}
printf("%f的平方根:%f.5/n",x1);
}
/* 上题的另一种算法 */
#define Epsilon 1.0E-6 /*控制解的精度*/
#include
#include
main()
{
float num,pre,this;
do
{
scanf("%f",&num);/*输入要求平方根的数*/
}while(num<0);
if (num==0)
printf("the root is 0");
else
{
this=1;
do
{
pre=this;
this=(pre+num/pre)/2;
}while(fabs(pre-this)>Epsilon);/*用解的精度,控制循环次数*/
}
printf("the root is %f",this);
}
用牛顿迭代法 求方程 2*x*x*x-4*x*x+3*x-6 的根
/* 牛顿迭代法 */
#define Epsilon 1.0E-6 /*控制解的精度*/
#include
main()
{
float x1,x0=1.5;
x1=x0-(2*x0*x0*x0-4*x0*x0+3*x0-6)/(6*x0*x0-8*x0+3);
while(fabs(x1-x0>=Epsilon)
{
x0=x1;
x1=x0-(2*x0*x0*x0-4*x0*x0+3*x0-6)/(6*x0*x0-8*x0+3);
}
printf("方程的根为%f/n",x1);
}
用二分法求上题
/* 二分法 */
#define Epsilon 1.0E-5 /*控制解的精度*/
#include
main()
{
folat x1,x2,x0,f1,f2,f0;
x0=(x1+x2)/2;
f0=2*x0*x0*x0-4*x0*x0+3*x0-6; /* 求中点的函数值 */
while(fabs(f0)>=Epsilon)
{
if(f0*f1<0)
{ x2=x0;
f2=2*x2*x2*x2-4*x2*x2+3*x2-6;
}
if(f0*f2<0)
{ x1=x0;
f1=2*x1*x1*x1-4*x1*x1+3*x1-6;
}
x0=(x1+x2)/2;
f0=2*x0*x0*x0-4*x0*x0+3*x0-6;
}
printf("用二分法求得方程的根:%f/n",x0);
}
*
***
******
********
******
***
*
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程序分析:先把图形分成两部分来看待,前四行一个规律,后三行一个规律,利
用双重for循环,第一层控制行,第二层控制列。
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程序源代码:
main()
{
int i,j,k;
for(i=0;i<=3;i++)
{
for(j=0;j<=2-i;j++)
printf(" ");
for(k=0;k<=2*i;k++)
printf("*");
printf("/n");
}
for(i=0;i<=2;i++)
{
for(j=0;j<=i;j++)
printf(" ");
for(k=0;k<=4-2*i;k++)
printf("*");
printf("/n");
}
}
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程序分析:同29例
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程序源代码:
main( )
{
long ge,shi,qian,wan,x;
scanf("%ld",&x);
wan=x/10000;
qian=x%10000/1000;
shi=x%100/10;
ge=x%10;
if (ge==wan&&shi==qian)/*个位等于万位并且十位等于千位*/
printf("this number is a huiwen/n");
else
printf("this number is not a huiwen/n");
}
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程序分析:用情况语句比较好,如果第一个字母一样,则判断用情况语句或if语
句判断第二个字母。
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程序源代码:
#include
void main()
{
char letter;
printf("please input the first letter of someday/n");
while ((letter=getch())!='Y') /*当所按字母为Y时才结束*/
{ switch (letter)
{case 'S':printf("please input second letter/n");
if((letter=getch())=='a')
printf("saturday/n");
else if ((letter=getch())=='u')
printf("sunday/n");
else printf("data error/n");
break;
case 'F':printf("friday/n");break;
case 'M':printf("monday/n");break;
case 'T':printf("please input second letter/n");
if((letter=getch())=='u')
printf("tuesday/n");
else if ((letter=getch())=='h')
printf("thursday/n");
else printf("data error/n");
break;
case 'W':printf("wednesday/n");break;
default: printf("data error/n");
}
}
}
hurry up!
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程序源代码:
#include
void main(void)
{
int color;
for (color = 0; color < 8; color++)
{
textbackground(color); /*设置文本的背景颜色*/
cprintf("This is color %d/r/n", color);
cprintf("ress any key to continue/r/n");
getch(); /*输入字符看不见*/
}
}
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程序源代码:
#include
void main(void)
{
clrscr(); /*清屏函数*/
textbackground(2);
gotoxy(1, 5); /*定位函数*/
cprintf("Output at row 5 column 1/n");
textbackground(3);
gotoxy(20, 10);
cprintf("Output at row 10 column 20/n");
}
题目:练习函数调用
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程序源代码:
#include
void hello_world(void)
{
printf("Hello, world!/n");
}
void three_hellos(void)
{
int counter;
for (counter = 1; counter <= 3; counter++)
hello_world();/*调用此函数*/
}
void main(void)
{
three_hellos();/*调用此函数*/
}
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程序源代码:
#include
void main(void)
{
int color;
for (color = 1; color < 16; color++)
{
textcolor(color);/*设置文本颜色*/
cprintf("This is color %d/r/n", color);
}
textcolor(128 + 15);
cprintf("This is blinking/r/n");
}
题目:求100之内的素数
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程序源代码:
#include
#include "math.h"
#define N 101
main()
{
int i,j,line,a[N];
for(i=2;i
for(i=2;i
for(j=i+1;j
{
if(a!=0&&a[j]!=0)
if(a[j]%a==0)
a[j]=0;}
printf("/n");
for(i=2,line=0;i
{
if(a!=0)
{printf("%5d",a);
line++;}
if(line==10)
{printf("/n");
line=0;}
}
}
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程序分析:可以利用选择法,即从后9个比较过程中,选择一个最小的与第一个
元素交换,下次类推,即用第二个元素与后8个进行比较,并进行交换。
程序源代码:
#define N 10
main()
{int i,j,min,tem,a[N];
/*input data*/
printf("please input ten num:/n");
for(i=0;i
{
printf("a[%d]=",i);
scanf("%d",&a);}
printf("/n");
for(i=0;i
printf("%5d",a);
printf("/n");
/*sort ten num*/
for(i=0;i
{min=i;
for(j=i+1;j
if(a[min]>a[j]) min=j;
tem=a;
a=a[min];
a[min]=tem;
}
/*output data*/
printf("After sorted /n");
for(i=0;i
printf("%5d",a);
}
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程序分析:利用双重for循环控制输入二维数组,再将a累加后输出。
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程序源代码:
main()
{
float a[3][3],sum=0;
int i,j;
printf("please input rectangle element:/n");
for(i=0;i<3;i++)
for(j=0;j<3;j++)
scanf("%f",&a[j]);
for(i=0;i<3;i++)
sum=sum+a;
printf("duijiaoxian he is %6.2f",sum);
}
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程序分析:首先判断此数是否大于最后一个数,然后再考虑插入中间的数的情况
,插入后此元素之后的数,依次后移一个位置。
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程序源代码:
main()
{
int a[11]={1,4,6,9,13,16,19,28,40,100};
int temp1,temp2,number,end,i,j;
printf("original array is:/n");
for(i=0;i<10;i++)
printf("%5d",a);
printf("/n");
printf("insert a new number:");
scanf("%d",&number);
end=a[9];
if(number>end)
a[10]=number;
else
{for(i=0;i<10;i++)
{ if(a>number)
{temp1=a;
a=number;
for(j=i+1;j<11;j++)
{temp2=a[j];
a[j]=temp1;
temp1=temp2;
}
break;
}
}
}
for(i=0;i<11;i++)
printf("%6d",a);
}
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程序分析:用第一个与最后一个交换。
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程序源代码:
#define N 5
main()
{ int a[N]={9,6,5,4,1},i,temp;
printf("/n original array:/n");
for(i=0;i
printf("%4d",a);
for(i=0;i
{temp=a;
a=a[N-i-1];
a[N-i-1]=temp;
}
printf("/n sorted array:/n");
for(i=0;i
printf("%4d",a);
}
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程序源代码:
#include "stdio.h"
varfunc()
{
int var=0;
static int static_var=0;
printf("/40:var equal %d /n",var);
printf("/40:static var equal %d /n",static_var);
printf("/n");
var++;
static_var++;
}
void main()
{int i;
for(i=0;i<3;i++)
varfunc();
}
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程序源代码:
#include "stdio.h"
main()
{int i,num;
num=2;
for (i=0;i<3;i++)
{ printf("/40: The num equal %d /n",num);
num++;
{
auto int num=1;
printf("/40: The internal block num equal %d /n",num);
num++;
}
}
}
C语言的学基础,100个经典的算法-2
程序源代码:
#include "stdio.h"
main()
{
int i,num;
num=2;
for(i=0;i<3;i++)
{
printf("/40: The num equal %d /n",num);
num++;
{
static int num=1;
printf("/40:The internal block num equal %d/n",num);
num++;
}
}
}
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程序源代码:
#include "stdio.h"
int a,b,c;
void add()
{ int a;
a=3;
c=a+b;
}
void main()
{ a=b=4;
add();
printf("The value of c is equal to %d/n",c);
}
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程序源代码:
void main()
{
register int i;
int tmp=0;
for(i=1;i<=100;i++)
tmp+=i;
printf("The sum is %d/n",tmp);
}
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程序源代码:
#include "stdio.h"
#define TRUE 1
#define FALSE 0
#define SQ(x) (x)*(x)
void main()
{
int num;
int again=1;
printf("/40: Program will stop if input value less than 50./n");
while(again)
{
printf("/40lease input number==>");
scanf("%d",&num);
printf("/40:The square for this number is %d /n",SQ(num));
if(num>=50)
again=TRUE;
else
again=FALSE;
}
}
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程序源代码:
#include "stdio.h"
#define exchange(a,b)
{ / /*宏定义中允许包含两道衣裳命令的情形,此时必须在最右边加上"/"*/
int t;/
t=a;/
a=b;/
b=t;/
}
void main(void)
{
int x=10;
int y=20;
printf("x=%d; y=%d/n",x,y);
exchange(x,y);
printf("x=%d; y=%d/n",x,y);
}
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程序源代码:
#define LAG >
#define SMA <
#define EQ ==
#include "stdio.h"
void main()
{ int i=10;
int j=20;
if(i LAG j)
printf("/40: %d larger than %d /n",i,j);
else if(i EQ j)
printf("/40: %d equal to %d /n",i,j);
else if(i SMA j)
printf("/40:%d smaller than %d /n",i,j);
else
printf("/40: No such value./n");
}
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程序源代码:
#include "stdio.h"
#define MAX
#define MAXIMUM(x,y) (x>y)?x:y
#define MINIMUM(x,y) (x>y)?y:x
void main()
{ int a=10,b=20;
#ifdef MAX
printf("/40: The larger one is %d/n",MAXIMUM(a,b));
#else
printf("/40: The lower one is %d/n",MINIMUM(a,b));
#endif
#ifndef MIN
printf("/40: The lower one is %d/n",MINIMUM(a,b));
#else
printf("/40: The larger one is %d/n",MAXIMUM(a,b));
#endif
#undef MAX
#ifdef MAX
printf("/40: The larger one is %d/n",MAXIMUM(a,b));
#else
printf("/40: The lower one is %d/n",MINIMUM(a,b));
#endif
#define MIN
#ifndef MIN
printf("/40: The lower one is %d/n",MINIMUM(a,b));
#else
printf("/40: The larger one is %d/n",MAXIMUM(a,b));
#endif
}
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程序源代码:
test.h 文件如下:
#define LAG >
#define SMA <
#define EQ ==
#include "test.h" /*一个新文件50.c,包含test.h*/
#include "stdio.h"
void main()
{ int i=10;
int j=20;
if(i LAG j)
printf("/40: %d larger than %d /n",i,j);
else if(i EQ j)
printf("/40: %d equal to %d /n",i,j);
else if(i SMA j)
printf("/40:%d smaller than %d /n",i,j);
else
printf("/40: No such value./n");
}
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程序分析:0&0=0; 0&1=0; 1&0=0; 1&1=1
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程序源代码:
#include "stdio.h"
main()
{
int a,b;
a=077;
b=a&3;
printf("/40: The a & b(decimal) is %d /n",b);
b&=7;
printf("/40: The a & b(decimal) is %d /n",b);
}
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程序分析:0|0=0; 0|1=1; 1|0=1; 1|1=1
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程序源代码:
#include "stdio.h"
main()
{
int a,b;
a=077;
b=a|3;
printf("/40: The a & b(decimal) is %d /n",b);
b|=7;
printf("/40: The a & b(decimal) is %d /n",b);
}
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程序分析:0^0=0; 0^1=1; 1^0=1; 1^1=0
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程序源代码:
#include "stdio.h"
main()
{
int a,b;
a=077;
b=a^3;
printf("/40: The a & b(decimal) is %d /n",b);
b^=7;
printf("/40: The a & b(decimal) is %d /n",b);
}
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程序分析:可以这样考虑:
(1)先使a右移4位。
(2)设置一个低4位全为1,其余全为0的数。可用~(~0<<4)
(3)将上面二者进行&运算。
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程序源代码:
main()
{
unsigned a,b,c,d;
scanf("%o",&a);
b=a>>4;
c=~(~0<<4);
d=b&c;
printf("%o/n%o/n",a,d);
}
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程序分析:~0=1; ~1=0;
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程序源代码:
#include "stdio.h"
main()
{
int a,b;
a=234;
b=~a;
printf("/40: The a's 1 complement(decimal) is %d /n",b);
a=~a;
printf("/40: The a's 1 complement(hexidecimal) is %x /n",a);
}
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程序源代码:
/*circle*/
#include "graphics.h"
main()
{
int driver,mode,i;
float j=1,k=1;
driver=VGA;mode=VGAHI;
initgraph(&driver,&mode,"");
setbkcolor(YELLOW);
for(i=0;i<=25;i++)
{
setcolor(8);
circle(310,250,k);
k=k+j;
j=j+0.3;
}
}
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程序源代码:
#include "graphics.h"
main()
{
int driver,mode,i;
float x0,y0,y1,x1;
float j=12,k;
driver=VGA;mode=VGAHI;
initgraph(&driver,&mode,"");
setbkcolor(GREEN);
x0=263;y0=263;y1=275;x1=275;
for(i=0;i<=18;i++)
{
setcolor(5);
line(x0,y0,x0,y1);
x0=x0-5;
y0=y0-5;
x1=x1+5;
y1=y1+5;
j=j+10;
}
x0=263;y1=275;y0=263;
for(i=0;i<=20;i++)
{
setcolor(5);
line(x0,y0,x0,y1);
x0=x0+5;
y0=y0+5;
y1=y1-5;
}
}
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程序分析:利用for循环控制100-999个数,每个数分解出个位,十位,百位。
___________________________________________________________________
程序源代码:
#include "graphics.h"
main()
{
int x0,y0,y1,x1,driver,mode,i;
driver=VGA;mode=VGAHI;
initgraph(&driver,&mode,"");
setbkcolor(YELLOW);
x0=263;y0=263;y1=275;x1=275;
for(i=0;i<=18;i++)
{
setcolor(1);
rectangle(x0,y0,x1,y1);
x0=x0-5;
y0=y0-5;
x1=x1+5;
y1=y1+5;
}
settextstyle(DEFAULT_FONT,HORIZ_DIR,2);
outtextxy(150,40,"How beautiful it is!");
line(130,60,480,60);
setcolor(2);
circle(269,269,137);
}