# 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;
}

#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;
}

2.2001；2004；

3.因为首先，整型占4个字节，字符型占1个；并且q与p不同，q指向的是一维数组，进行++操作后，跳过的是一整个数组，而不是跳过一个元素。

#define _CRT_SECURE_NO_WARNINGS
#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;

}

#define _CRT_SECURE_NO_WARNINGS
#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;

}

2.不能；

3.交换了。

实验3.2:1.存放的是字符串的首地址；计算的是地址变量s1所占的字节数；统计的是所有有效字符的个数；

2.可以；

3.交换的是地址；在内存存储单元中没有交换。

#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;
if (strlen(str) != 18)
return 0;
for (i = 0; i < 18; i++)
{
if ((str[i] >= '0' && str[i] <= '9') || str[i] == 'X')
continue;
else
return 0;
}
return 1;
}

#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_s(str);
flag = is_palindrome(str);
if (flag)
printf("YES\n");
else
printf("NO\n");
return 0;
}
int is_palindrome(char* s)
{
int i,j;
j = strlen(s);
for (i = 0;s[i]!='\0'; i++)
{
if (s[i] == s[j - i-1])
continue;
else
return 0;
}
return 1;
}

#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_s(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,j=0;
for (i = 0; s[i] != '\0'; i++)
j++;
for (i = 0; i < j; i++)
{
if ((s[i] >= 'a' && s[i] < 'z') || (s[i] >= 'A' && s[i] < 'Z'))
s[i] = s[i] + 1;
else if ((s[i] == 'z') || (s[i] == 'Z'))
s[i] = s[i] - 25;
}
}
void decoder(char* s)
{
int i, j = 0;
for (i = 0; s[i] != '\0'; i++)
j++;
for (i = 0; i < j; i++)
{
if ((s[i] > 'a' && s[i] <= 'z') || (s[i] > 'A' && s[i] <= 'Z'))
s[i] = s[i] - 1;
else if ((s[i] == 'a') || (s[i] == 'A'))
s[i] = s[i] + 25;
}
}

posted @ 2022-06-07 18:54  唐卉宁  阅读(17)  评论(3编辑  收藏  举报