C语言100个算法经典例题(九)
【程序81】809*??=800*??+9*??+1
题目:809*??=800*??+9*??+1 其中??代表的两位数,8*??的结果为两位数,9*??的结果为3位数。求??代表
的两位数,及809*??后的结果。
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
output(long b,long i)
{ printf("\n%ld/%ld=809*%ld+%ld",b,i,i,b%i);
}
main()
{long int a,b,i;
a=809;
for(i=10;i<100;i++)
{b=i*a+1;
if(b>=1000&&b<=10000&&8*i<100&&9*i>=100)
output(b,i); }
}
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【程序82】题目:八进制转换为十进制
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
main()
{ char *p,s[6];int n;
p=s;
gets(p);
n=0;
while(*(p)!='\0')
{n=n*8+*p-'0';
p++;}
printf("%d",n);
}
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【程序83】题目:求0—7 所能组成的奇数个数。
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
main()
{
long sum=4,s=4;
int j;
for(j=2;j<=8;j++)/*j is place of number*/
{ printf("\n%ld",sum);
if(j<=2)
s*=7;
else
s*=8;
sum+=s;}
printf("\nsum=%ld",sum);
}
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【程序84】题目:一个偶数总能表示为两个素数之和。
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include "stdio.h"
#include "math.h"
main()
{ int a,b,c,d;
scanf("%d",&a);
for(b=3;b<=a/2;b+=2)
{ for(c=2;c<=sqrt(b);c++)
if(b%c==0) break;
if(c>sqrt(b))
d=a-b;
else
break;
for(c=2;c<=sqrt(d);c++)
if(d%c==0) break;
if(c>sqrt(d))
printf("%d=%d+%d\n",a,b,d);
}
}
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【程序85】题目:判断一个素数能被几个9 整除
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
main()
{ long int m9=9,sum=9;
int zi,n1=1,c9=1;
scanf("%d",&zi);
while(n1!=0)
{ if(!(sum%zi))
n1=0;
else
{m9=m9*10;
sum=sum+m9;
c9++;
}
}
printf("%ld,can be divided by %d \"9\"",sum,c9);
}
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【程序86】题目:两个字符串连接程序
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include "stdio.h"
main()
{char a[]="acegikm";
char b[]="bdfhjlnpq";
char c[80],*p;
int i=0,j=0,k=0;
while(a[i]!='\0'&&b[j]!='\0')
{if (a[i] { c[k]=a[i];i++;}
else
c[k]=b[j++];
k++;
}
c[k]='\0';
if(a[i]=='\0')
p=b+j;
else
p=a+i;
strcat(c,p);
puts(c);
}
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【程序87】题目:回答结果(结构体变量传递)
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include "stdio.h"
struct student
{ int x;
char c;
} a;
main()
{a.x=3;
a.c='a';
f(a);
printf("%d,%c",a.x,a.c);
}
f(struct student b)
{
b.x=20;
b.c='y';
}
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【程序88】读取7 个数,打印*
题目:读取7个数(1—50)的整数值,每读取一个值,程序打印出该值个数的*。
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
main()
{int i,a,n=1;
while(n<=7)
{ do {
scanf("%d",&a);
}while(a<1||a>50);
for(i=1;i<=a;i++)
printf("*");
printf("\n");
n++;}
getch();
} 48
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【程序89】公司加密数据
题目:某个公司采用公用电话传递数据,数据是四位的整数,在传递过程中是加密的,加密规则如下:每
位数字都加上5,然后用和除以10的余数代替该数字,再将第一位和第四位交换,第二位和第三位交换。
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
main()
{int a,i,aa[4],t;
scanf("%d",&a);
aa[0]=a%10;
aa[1]=a%100/10;
aa[2]=a%1000/100;
aa[3]=a/1000;
for(i=0;i<=3;i++)
{aa[i]+=5;
aa[i]%=10;
}
for(i=0;i<=3/2;i++)
{t=aa[i];
aa[i]=aa[3-i];
aa[3-i]=t;
}
for(i=3;i>=0;i--)
printf("%d",aa[i]);
}
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【程序90】题目:专升本一题,读结果。
1.程序分析:
![](https://images.cnblogs.com/OutliningIndicators/ContractedBlock.gif)
#include "stdio.h"
#define M 5
main()
{int a[M]={1,2,3,4,5};
int i,j,t;
i=0;j=M-1;
while(i {t=*(a+i);
*(a+i)=*(a+j);
*(a+j)=t;
i++;j--;
}
for(i=0;i printf("%d",*(a+i));
}