实验五

实验任务一

#include <stdio.h>
#define N 4
int main()
{
int x[N] = {1, 9, 8, 4};
int i;
int *p;
// 方式1:通过数组名和下标遍历输出数组元素
for (i = 0; i < N; ++i)
printf("%d", x[i]);
printf("\n");
// 方式2:通过指针变量遍历输出数组元素 (写法1)
for (p = x; p < x + N; ++p)
printf("%d", *p);

printf("\n");
// 方式2:通过指针变量遍历输出数组元素(写法2)
p = x;
for (i = 0; i < N; ++i)
printf("%d", *(p + i));
printf("\n");
// 方式2:通过指针变量遍历输出数组元素(写法3)
p = x;
for (i = 0; i < N; ++i)
printf("%d", p[i]);
printf("\n");
return 0;
} 

程序运行截图

程序源码

#include <stdio.h>
int main()
{
int x[2][4] = {{1, 9, 8, 4}, {2, 0, 4, 9}};
int i, j;
int *p; // 指针变量,存放int类型数据的地址
int(*q)[4]; // 指针变量,指向包含4个int型元素的一维数组
// 使用数组名、下标访问二维数组元素
for (i = 0; i < 2; ++i)
{
for (j = 0; j < 4; ++j)
printf("%d", x[i][j]);
printf("\n");
}
// 使用指针变量p间接访问二维数组元素
for (p = &x[0][0], i = 0; p < &x[0][0] + 8; ++p, ++i)
{
printf("%d", *p);
if ((i + 1) % 4 == 0)
printf("\n");
}
// 使用指针变量q间接访问二维数组元素
for (q = x; q < x + 2; ++q)
{
for (j = 0; j < 4; ++j)
    printf("%d", *(*q + j));
printf("\n");
}
return 0;
} 

程序运行截图

实验任务2

#include <stdio.h>
#include <string.h>
#define N 80
int main()
{
char s1[] = "Learning makes me happy";
char s2[] = "Learning makes me sleepy";
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;
}

程序运行截图

s1存放了字符数组的首元素地址,sizeof(s1)计算的是地址变量的大小 strlen(s1)统计的是s1所指向数组中不包括‘\0’的长度

程序源码

#include <stdio.h>
#include <string.h>
#define N 80
int main()
{
char *s1 = "Learning makes me happy";
char *s2 = "Learning makes me sleepy";
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;
}

程序运行截图

实验任务3

程序源码

#include <stdio.h>
void str_cpy(char *target, const char *source);
void str_cat(char *str1, char *str2);
int main()
{
char s1[80], s2[20] = "1984";
str_cpy(s1, s2);
puts(s1);
str_cat(s1, " Animal Farm");
puts(s1);
return 0;
}
void str_cpy(char *target, const char *source)
{
while (*target++ = *source++)
;
}
void str_cat(char *str1, char *str2)
{
while (*str1)
str1++;
while (*str1++ = *str2++)
; 
} 

程序运行截图

实验任务4

程序源码

#include <stdio.h>
#define N 80
int func(char *);
int main()
{
char str[80];
while (gets(str) != NULL)
{
if (func(str))
printf("yes\n");
else
printf("no\n");
}
return 0;
}
int func(char *str)
{
char *begin, *end;
begin = end = str;
while (*end)
end++;
end--;
while (begin < end)
{
if (*begin != *end)
return 0;
else
{
begin++;
end--;
}
}
return 1;
}

程序运行截图

 实验任务5

程序源码

#include <stdio.h>
#define N 80
void func(char *);
int main()
{
char s[N];
while (scanf("%s", s) != EOF)
{
func(s);
puts(s);
}
return 0;
}
void func(char *str)
{
int i;
char *p1, *p2, *p;
p1 = str;
while (*p1 == '*')
p1++;
p2 = str;
while (*p2)
p2++;
p2--;
while (*p2 == '*')
p2--;
p = str;
i = 0;
while (p < p1)
{
str[i] = *p;
p++;
i++;
}
while (p <= p2)
{
if (*p != '*')
{
str[i] = *p;
i++;
}
p++;
}
while (*p != '\0')
{
str[i] = *p;
p++;
i++;
}
str[i] = '\0';
} 

程序运行截图

实验任务6

程序源码

#include <stdio.h>
#include <string.h>
void sort(char *name[], int n);
int main()
{
char *course[4] = {"C Program",
"C++ Object Oriented Program",
"Operating System",
"Data Structure and Algorithms"};
int i;
sort(course, 4);
for (i = 0; i < 4; i++)
printf("%s\n", course[i]);
return 0;
}
void sort(char *name[], int n)
{
int i, j;
char *tmp;
for (i = 0; i < n - 1; ++i)
for (j = 0; j < n - 1 - i; ++j)
if (strcmp(name[j], name[j + 1]) > 0)
{
tmp = name[j];
name[j] = name[j + 1];
name[j + 1] = tmp;
}
}

程序运行截图

是内存中的存储位置发生了交换

实验任务7

程序源码

#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 cnt=0;
    while(*str){
        if((*str>='0'&&*str<='9')||*str=='X'){
            str++;
            cnt++;
        }
        else{
            return 0;
        }
    }
    if(cnt!=18) return 0;
    return 1;
}

程序运行截图

实验任务8

程序源码

#include <stdio.h>
#define N 80
void encoder(char *s); 
void decoder(char *s); 
int main()
{
    char words[N];
    printf("杈撳叆鑻辨枃鏂囨湰: ");
    gets(words);
    printf("缂栫爜鍚庣殑鑻辨枃鏂囨湰: ");
    encoder(words); 
    printf("%s\n", words);
    printf("瀵圭紪鐮佸悗鐨勮嫳鏂囨枃鏈В鐮? ");
    decoder(words); 
    printf("%s\n", words);
    return 0;
}

void encoder(char *s)
{
 
    while (*s)
    {
        if(*s>='a'&&*s<='z'||*s>='A'&&*s<='Z'){
            if(*s=='z'||*s=='Z'){
                *s-=24;
            }
            else{
                *s=*s+1;
            }
        }
        s++;
    }
}

void decoder(char *s)
{
    
    while (*s)
    {
         if(*s>='a'&&*s<='z'||*s>='A'&&*s<='Z'){
            if(*s=='a'||*s=='A'){
                *s+=24;
            }
            else{
                *s=*s-1;
            }
        }
        s++;
    } 
}

 

posted @ 2023-05-11 14:58  谈伊敉  阅读(10)  评论(1编辑  收藏  举报