1.#include <stdio.h>
int main()
{
int n;
printf("璇疯緭鍏鐨勫€硷細\n");
scanf("%d",&n);
int i = 1,count = 0,temp;
while(i<=n)
{
temp = i;
while(temp!=0)
{
if(temp%10 == 9)
{
count++;
}
temp = temp/10;
}
i++;
}
printf("the result is:%d",count);
return 0;
}
#include <stdio.h>
int main()
{
int n;
printf("输入人数:\n");
scanf("%d",&n);
int main()
{
int n;
printf("输入人数:\n");
scanf("%d",&n);
int a[1000];
int i,temp;
int count = 0;
temp = n;
for(i = 0;i < n;i++)
{
a[i] = i+1;
}
i = 0;
while (n>1)
{
if(a[i] != 0)
{
count++;
}
if(count == 3)
{
a[i] = 0;
count = 0;
n--;
}
i++;
if(i == temp)
{
i = 0;
}
}
for(i = 0;i < temp;i++)
{
if(a[i] != 0)
{
printf("余下的为:%d号\n",a[i]);
}
}
return 0;
}
3
#include <stdio.h>
float paixu(float b[5]);//声明paixu函数
int main()
{
float a[5];//存放5个数包括小数
int i;
printf("请输入5个数:\n");
for(i = 0;i < 5;i++)//输入5个数
scanf("%f",&a[i]);
paixu(a);
printf("排序后结果是:\n");
for(i = 0;i < 5;i++)
printf("%2.1f\t",a[i]);//以2位,小数部分一位的格式输出,制表
printf("\n");
for(i = 0;i < 5;i++)
printf("%2.1f\t",a[i]);//以2位,小数部分一位的格式输出,制表
printf("\n");
return 0;
}
float paixu(float b[])//从小到大排序,实参传入形参b[]
{
int i, j;
float t = 0.0;//t用来交换数
for(i = 0;i < 5;i++)
{
for(j = i + 1; j < 5;j++)//将每一个数与后面的数字依次比较
{
if(b[j] < b[i])//将较小的数存放在数组
{
t = b[i];
b[i] = b[j];
b[j] = t;
}
}
}
}
4
#include <stdio.h>
int main()
{
int i;
int j = 1;
for(i = 2;i <= 100;i++)
{
for(j = 2;j <i;j++)
if(i%j == 0)
{
break;
}
if(j == i)
{
printf("%d ",i);
}
}
printf("\n");
return 0;
}
5
#include <stdio.h>
int main()
{
int i;
int j;
int sum=0;
int temp;
for(i = 1;i <= 1000;i++)
{
temp = i;
for(j = 1;j <= temp/2;j++)
{
if(temp%j == 0)
{
sum+=j;
}
}
if(sum == i)
{
printf("%d ",i);
}
sum = 0;
}
printf("\n");
return 0;
1.#include <stdio.h>
#include <string.h>
char *reserve(char *s)
{
int i; //定义循环变量
int n = strlen(s)/2; //循环次数只能到字符串长度的一半,否则待会交换又会换回来
char tmp;
{
int i; //定义循环变量
int n = strlen(s)/2; //循环次数只能到字符串长度的一半,否则待会交换又会换回来
char tmp;
for(i = 0; i <= n; i++) //这里用的是字符数组处理字符串,将字符串的首字符和最后一个字符交换,注意交换的次数
{
tmp = s[i];
s[i] = s[strlen(s)-i-1];
s[strlen(s)-i-1] = tmp;
}
{
tmp = s[i];
s[i] = s[strlen(s)-i-1];
s[strlen(s)-i-1] = tmp;
}
return s; //结果返回交换后的字符串
}
}
int main()
{
char str[20];
{
char str[20];
printf("Please input a string:\n");
scanf("%s", str);
printf("\nThe reserved string is:\n%s\n", reserve(str));
return 0;
}
2.#include <stdio.h>
#include <string.h>
#define N 20
}
2.#include <stdio.h>
#include <string.h>
#define N 20
char *hex(char *s,int num,int n)
{
char tmp;
int i = 0;
{
char tmp;
int i = 0;
while (num != 0)
{
s[i] = num % n;
if(s[i] <= 9)
{
s[i]=s[i]+'0';
}
else
{
switch(s[i])
{
case 10:s[i]='A';
break;
case 11:s[i]='B';
break;
case 12:s[i]='C';
break;
case 13:s[i]='D';
break;
case 14:s[i]='E';
break;
case 15:s[i]='F';
break;
default:break;
}
}
num = num / n;
i++;
}
{
s[i] = num % n;
if(s[i] <= 9)
{
s[i]=s[i]+'0';
}
else
{
switch(s[i])
{
case 10:s[i]='A';
break;
case 11:s[i]='B';
break;
case 12:s[i]='C';
break;
case 13:s[i]='D';
break;
case 14:s[i]='E';
break;
case 15:s[i]='F';
break;
default:break;
}
}
num = num / n;
i++;
}
s[i]='\0';
for(i=0;i<strlen(s)/2;i++)
{
tmp = s[i];
s[i] = s[strlen(s)-i-1];
s[strlen(s)-i-1] = tmp;
}
{
tmp = s[i];
s[i] = s[strlen(s)-i-1];
s[strlen(s)-i-1] = tmp;
}
return s;
}
}
int main()
{
int num;
int n;
char s[N];
{
int num;
int n;
char s[N];
printf("请输入一个整数和进制(中间以空格间隔):\n");
scanf("%d %d",&num,&n);
printf("转换后的字符串为:\n%s\n",hex(s,num,n));
return 0;
}
3.#include <stdio.h>
#include <string.h>
int main()
{
char a[100];
printf("请输入字符串\n");
scanf("%s",a);
char * c = a;
char b[10];
printf("请输入子串\n");
scanf("%s",b);
char * d = b;
int n;
int num = 0;
n = strlen(d);
while(strlen(c) > 0)
{
if(strncmp(c,d,n) == 0)
{
num++;
c += n;
}
else
{
c++;
}
}
printf("%d\n",num);
return 0;
}
4.#include <stdio.h>
#include <string.h>
#include <stdlib.h>
}
3.#include <stdio.h>
#include <string.h>
int main()
{
char a[100];
printf("请输入字符串\n");
scanf("%s",a);
char * c = a;
char b[10];
printf("请输入子串\n");
scanf("%s",b);
char * d = b;
int n;
int num = 0;
n = strlen(d);
while(strlen(c) > 0)
{
if(strncmp(c,d,n) == 0)
{
num++;
c += n;
}
else
{
c++;
}
}
printf("%d\n",num);
return 0;
}
4.#include <stdio.h>
#include <string.h>
#include <stdlib.h>
int main()
{
char *str[] = { "I", "am","from","shanghai" ,NULL};
int i = 0;
int j = 0;
int len = 0;
char *temp;
while (str[i] != NULL)
{
i++;
len++;
}
for(i = 0, j = len - 1; j > i; i++,j--)
{
temp =*(str+i);
*(str+i) = *(str+j);
*(str+j) = temp;
}
for(i = 0; i < len; i++)
{
printf("%s ", *(str+i));
}
printf("\n");
{
char *str[] = { "I", "am","from","shanghai" ,NULL};
int i = 0;
int j = 0;
int len = 0;
char *temp;
while (str[i] != NULL)
{
i++;
len++;
}
for(i = 0, j = len - 1; j > i; i++,j--)
{
temp =*(str+i);
*(str+i) = *(str+j);
*(str+j) = temp;
}
for(i = 0; i < len; i++)
{
printf("%s ", *(str+i));
}
printf("\n");
return 0;
}
5.
#include <stdio.h>
#include <string.h>
}
5.
#include <stdio.h>
#include <string.h>
int substr(char str[255],char s[255],int k);
int main()
{
char str[255];
char head[255];
char tail[255];
int x,y;
int i = 0,t;
{
char str[255];
char head[255];
char tail[255];
int x,y;
int i = 0,t;
printf("enter a string:\n");
scanf("%s",str);
printf("enter head:\n");
scanf("%s",head);
printf("enter tail:\n");
scanf("%s",tail);
scanf("%s",str);
printf("enter head:\n");
scanf("%s",head);
printf("enter tail:\n");
scanf("%s",tail);
t = substr(str,head,0);
x = t - strlen(head);
y = substr(str,tail,t);
x = t - strlen(head);
y = substr(str,tail,t);
for(i = x;i < y;i++)
{
printf("%c",str[i]);
}
printf("\n");
{
printf("%c",str[i]);
}
printf("\n");
return 0;
}
int substr(char str[255],char s[255],int k)
{
char *p = str+k;
char *p1 = s;
int i = k;
int flag = 0,m;
while(*p != '\0')
{
if(*p == *p1 && flag == 0)
{
while(*p == *p1 && *p1 != '\0')
{
p++;
p1++;
i++;
}
if(*p1 == '\0')
{
flag = 1;
m = i;
}
}
else
{
p++;
i++;
}
{
p++;
i++;
}
}
return m;
}