# 第六次实验

1. 实验任务1
#include <stdio.h>
#define N 4

int main()
{
int x[N] = {1, 9, 8, 4};
int i;
int *p;
for(i=0; i<N; ++i)
printf("%d", x[i]);
printf("\n");
for(p=x; p<x+N; ++p)
printf("%d", *p);
printf("\n");
p = x;
for(i=0; i<N; ++i)
printf("%d", *(p+i));
printf("\n");
p = x;
for(i=0; i<N; ++i)
printf("%d", p[i]);
printf("\n");

return 0;
}

#include <stdio.h>
#define N 4

int main()
{
char x[N] = {'1', '9', '8', '4'};
int i;
char *p;
for(i=0; i<N; ++i)
printf("%c", x[i]);
printf("\n");
for(p=x; p<x+N; ++p)
printf("%c", *p);
printf("\n");
p = x;
for(i=0; i<N; ++i)
printf("%c", *(p+i));
printf("\n");
p = x;
for(i=0; i<N; ++i)
printf("%c", p[i]);
printf("\n");

return 0;
}

2. 实验任务2
#include <stdio.h>

int main()
{
int x[2][4] = { {1,9,8,4}, {2,0,2,2}} ;
int i, j;
int *p;
int (*q)[4];

for(i=0; i<2; ++i)
{
for(j=0; j<4; ++j)
printf("%d", x[i][j]);
printf("\n");
}

for(p = &x[0][0], i = 0; p < &x[0][0] + 8; ++p, ++i)
{
printf("%d", *p);
if( (i+1)%4 == 0)
printf("\n");
}
for(q=x; q<x+2; ++q)
{
for(j=0; j<4; ++j)
printf("%d", *(*q+j));
printf("\n");
}

return 0;
}

#include <stdio.h>

int main()
{
char x[2][4] = { {'1', '9', '8', '4'}, {'2', '0', '2', '2'} };
int i, j;
char *p;
char (*q)[4];
for(i=0; i<2; ++i)
{
for(j=0; j<4; ++j)
printf("%c", x[i][j]);
printf("\n");
}
for(p = &x[0][0], i = 0; p < &x[0][0] + 8; ++p, ++i)
{
printf("%c", *p);
if( (i+1)%4 == 0)
printf("\n");
}
for(q=x; q<x+2; ++q)
{
for(j=0; j<4; ++j)
printf("%c", *(*q+j));
printf("\n");
}

return 0;
}

3. 实验任务3
#include <stdio.h>
#include <string.h>
#define N 80

int main()
{
char s1[] = "C, I love u.";
char s2[] = "C, I hate u.";
char tmp[N];

printf("sizeof(s1) vs. strlen(s1): \n");
printf("sizeof(s1) = %d\n", sizeof(s1));
printf("strlen(s1) = %d\n", strlen(s1));

printf("\nbefore swap: \n");
printf("s1: %s\n", s1);
printf("s2: %s\n", s2);

printf("\nswapping...\n");
strcpy(tmp, s1);
strcpy(s1, s2);
strcpy(s2, tmp);

printf("\nafter swap: \n");
printf("s1: %s\n", s1);
printf("s2: %s\n", s2);

return 0;
}

#include <stdio.h>
#include <string.h>
#define N 80

int main()
{
char *s1 = "C, I love u.";
char *s2 = "C, I hate u.";
char *tmp;

printf("sizeof(s1) vs. strlen(s1): \n");
printf("sizeof(s1) = %d\n", sizeof(s1));
printf("strlen(s1) = %d\n", strlen(s1));

printf("\nbefore swap: \n");
printf("s1: %s\n", s1);
printf("s2: %s\n", s2);

printf("\nswapping...\n");
tmp = s1;
s1 = s2;
s2 = tmp;

printf("\nafter swap: \n");
printf("s1: %s\n", s1);
printf("s2: %s\n", s2);

return 0;
}

4. 实验任务4
#include <stdio.h>
#include <string.h>
#define N 5

int check_id(char *str);

int main()
{
char *pid[N] = {"31010120000721656X",
"330106199609203301",
"53010220051126571",
"510104199211197977",
"53010220051126133Y"};
int i;

for(i=0; i<N; ++i)
if( check_id(pid[i]) )
printf("%s\tTrue\n", pid[i]);
else
printf("%s\tFalse\n", pid[i]);

return 0;
}
int check_id(char *str)
{
int i;
char s[80];
strcpy(s,str);
if(strlen(str)!=18)
return     0;
for(i=0;i<18;i++)
{
if(s[i]!='X'&&s[i]<48||s[i]>57)
return 0;
}
return 1;

}

5. 实验任务5
#include <stdio.h>
#include <string.h>

#define N 80
int is_palindrome(char *s);

int main()
{
char str[N];
int flag;

printf("Enter a string:\n");
gets(str);

flag = is_palindrome(str);
if (flag)
printf("YES\n");
else
printf("NO\n");

return 0;
}

int is_palindrome(char *s)
{
int i,j;
char str[80],strp[80];
strcpy(str,s);
int k=strlen(s);
for(i=k-1;i>=0;i--)
strp[k-1-i]=str[i];
for(j=0;j<k;j++)
{
if(str[j]!=strp[j])
return 0;
}
return 1;

}

6. 实验任务6
#include <stdio.h>
#define N 80
void encoder(char *s);
void decoder(char *s);

int main()
{
char words[N];

printf("输入英文文本: ");
gets(words);

printf("编码后的英文文本: ");
encoder(words);
printf("%s\n", words);

printf("对编码后的英文文本解码: ");
decoder(words);
printf("%s\n", words);

return 0;
}

void encoder(char *s)
{
char *p;
p=s;
while(*p!=NULL)
{
if((*p>='a'&&*p<'z')||(*p>='A'&&*p<'Z'))
*p=*p+1;
else if(*p=='Z'||*p=='z')
*p=*p-25;
p=p+1;
}

}

void decoder(char *s)
{
char *p;
p=s;
while(*p!=NULL)
{
if((*p>='a'&&*p<'z')||(*p>='A'&&*p<'Z'))
*p=*p-1;
else if(*p=='Z'||*p=='z')
*p=*p+25;
p=p+1;
}

}

posted @ 2022-06-08 23:16  允楠  阅读(8)  评论(1编辑  收藏  举报