# 实验六

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;
}


1、2004
2、2001
3、字符类型不同，变量存储空间大小不同.

#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;
}


1、2004.
2、2017.

1、2001.
2、2005.

#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;
}


sizeof(s1)计算的是字符数组的长度，strlen(s1)计算的字符数组的有效长度

#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;
}


sizeof(s1)计算的是地址变量的大小；strlen(s1)统计的是s1字符数组有效长度；

#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,flag;

for(i=0;i<=17;i++)
{
if(str[i]>='0'&&str[i]<='9')
flag=1;
else
flag=0;
}

if(str[17]=='X')
flag=1;

if(strlen(str)==18&&flag==1)
return 1;
else
return 0;


}

#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=0,j;

j=strlen(s)-1;
while(i<=j&&s[i]==s[j])
{
i++;
j--;
}

if(i>=j)
return 1;
else
return 0;
}


#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)
{
int i;

for(i=0;s[i]!='\0';i++)
{
if(s[i]>='a'&&s[i]<='z')
{
if(s[i]!='z')
s[i]=s[i]+1;
else
s[i]='a';
}

if(s[i]>='A'&&s[i]<='Z')
{
if(s[i]!='Z')
s[i]=s[i]+1;
else
s[i]='A';
}
}
}

void decoder(char *s)
{
int i;

for(i=0;s[i]!='\0';i++)
{
if(s[i]>='a'&&s[i]<='z')
{
if(s[i]!='a')
s[i]=s[i]-1;
else
s[i]='z';
}

if(s[i]>='A'&&s[i]<='Z')
{
if(s[i]!='A')
s[i]=s[i]-1;
else
s[i]='Z';
}
}
}


posted @ 2022-06-13 22:34  王晶晶晶晶  阅读(10)  评论(2编辑  收藏  举报