实验五

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #define N 5
 4 
 5 void input(int x[], int n);
 6 void output(int x[], int n);
 7 void find_min_max(int x[], int n, int *pmin, int *pmax);
 8 
 9 int main() 
10 {
11     int a[N];
12     int min, max;
13 
14     printf("录入%d个数据:\n", N);
15     input(a, N);
16 
17     printf("数据是: \n");
18     output(a, N);
19 
20     printf("数据处理...\n");
21     find_min_max(a, N, &min, &max);
22 
23     printf("输出结果:\n");
24     printf("min = %d, max = %d\n", min, max);
25 
26     system("pause");
27     return 0;
28 }
29 void input(int x[], int n) {
30     int i;
31 
32     for(i = 0; i < n; ++i)
33         scanf("%d", &x[i]);
34 }
35 
36 void output(int x[], int n) {
37     int i;
38     
39     for(i = 0; i < n; ++i)
40         printf("%d ", x[i]);
41     printf("\n");
42 }
43 
44 void find_min_max(int x[], int n, int *pmin, int *pmax) {
45     int i;
46     
47     *pmin = *pmax = x[0];
48 
49     for(i = 1; i < n; ++i)
50         if(x[i] < *pmin)
51             *pmin = x[i];
52         else if(x[i] > *pmax)
53             *pmax = x[i];
54 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #define N 5
 4 
 5 void input(int x[], int n);
 6 void output(int x[], int n);
 7 int *find_max(int x[], int n);
 8 
 9 int main() {
10     int a[N];
11     int *pmax;
12 
13     printf("录入%d个数据:\n", N);
14     input(a, N);
15 
16     printf("数据是: \n");
17     output(a, N);
18 
19     printf("数据处理...\n");
20     pmax = find_max(a, N);
21 
22     printf("输出结果:\n");
23     printf("max = %d\n", *pmax);
24 
25     system("pause");
26     return 0;
27 }
28 void input(int x[], int n) {
29     int i;
30 
31     for(i = 0; i < n; ++i)
32         scanf("%d", &x[i]);
33 }
34 
35 void output(int x[], int n) {
36     int i;
37     
38     for(i = 0; i < n; ++i)
39         printf("%d ", x[i]);
40     printf("\n");
41 }
42 
43 int *find_max(int x[], int n) {
44     int max_index = 0;
45     int i;
46 
47     for(i = 1; i < n; ++i)
48         if(x[i] > x[max_index])
49             max_index = i;
50     
51     return &x[max_index];
52 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include <string.h>
 4 #define N 80
 5 
 6 int main() {
 7     char s1[] = "Learning makes me happy";
 8     char s2[] = "Learning makes me sleepy";
 9     char tmp[N];
10 
11     printf("sizeof(s1) vs. strlen(s1): \n");
12     printf("sizeof(s1) = %d\n", sizeof(s1));
13     printf("strlen(s1) = %d\n", strlen(s1));
14 
15     printf("\nbefore swap: \n");
16     printf("s1: %s\n", s1);
17     printf("s2: %s\n", s2);
18 
19     printf("\nswapping...\n");
20     strcpy(tmp, s1);
21     strcpy(s1, s2);
22     strcpy(s2, tmp);
23 
24     printf("\nafter swap: \n");
25     printf("s1: %s\n", s1);
26     printf("s2: %s\n", s2);
27 
28     system("pause");
29     return 0;
30 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include <string.h>
 4 #define N 80
 5 
 6 int main() {
 7     char *s1 = "Learning makes me happy";
 8     char *s2 = "Learning makes me sleepy";
 9     char *tmp;
10 
11     printf("sizeof(s1) vs. strlen(s1): \n");
12     printf("sizeof(s1) = %d\n", sizeof(s1));
13     printf("strlen(s1) = %d\n", strlen(s1));
14 
15     printf("\nbefore swap: \n");
16     printf("s1: %s\n", s1);
17     printf("s2: %s\n", s2);
18 
19     printf("\nswapping...\n");
20     tmp = s1;
21     s1 = s2;
22     s2 = tmp;
23 
24     printf("\nafter swap: \n");
25     printf("s1: %s\n", s1);
26     printf("s2: %s\n", s2);
27     system("pause");
28     return 0;
29 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include <string.h>
 4 int main() {
 5     int x[2][4] = {{1, 9, 8, 4}, {2, 0, 4, 9}};
 6     int i, j;
 7     int *ptr1;     // 指针变量，存放int类型数据的地址
 8     int(*ptr2)[4]; // 指针变量，指向包含4个int元素的一维数组
 9 
10     printf("输出1: 使用数组名、下标直接访问二维数组元素\n");
11     for (i = 0; i < 2; ++i) {
12         for (j = 0; j < 4; ++j)
13             printf("%d ", x[i][j]);
14         printf("\n");
15     }
16 
17     printf("\n输出2: 使用指向元素的指针变量p间接访问二维数组元素\n");
18     for (ptr1 = &x[0][0], i = 0; ptr1 < &x[0][0] + 8; ++ptr1, ++i) {
19         printf("%d ", *ptr1);
20 
21         if ((i + 1) % 4 == 0)
22             printf("\n");
23     }
24                          
25     printf("\n输出3: 使用指向一维数组的指针变量q间接访问二维数组元素\n");
26     for (ptr2 = x; ptr2 < x + 2; ++ptr2) {
27         for (j = 0; j < 4; ++j)
28             printf("%d ", *(*ptr2 + j));
29         printf("\n");
30     }
31 
32     system("pause");
33     return 0;
34 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #define N 80
 4 
 5 void replace(char *str, char old_char, char new_char); // 函数声明
 6 
 7 int main() {
 8     char text[N] = "c programming is difficult or not, it is a question.";
 9 
10     printf("原始文本: \n");
11     printf("%s\n", text);
12 
13     replace(text, 'i', '*'); // 函数调用 注意字符形参写法，单引号不能少
14 
15     printf("处理后文本: \n");
16     printf("%s\n", text);
17 
18     system("pause");
19     return 0;
20 }
21 
22 void replace(char *str, char old_char, char new_char) {
23     int i;
24 
25     while(*str) {
26         if(*str == old_char)
27             *str = new_char;
28         str++;
29     }
30 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #define N 80
 4 
 5 void str_trunc(char *str, char x);
 6 
 7 int main() {
 8     char str[N];
 9     char ch;
10 
11     printf("输入字符串: ");
12     gets(str);
13 
14     printf("输入一个字符: ");
15     ch = getchar();
16 
17     printf("截断处理...\n");
18     str_trunc(str, ch);
19 
20     printf("截断处理后的字符串: %s\n", str);
21 
22 
23     system("pause");
24     return 0;
25 }
26 
27 void str_trunc(char *str, char x) 
28 {
29     while(*str) 
30     {
31         if(*str == x)
32             *str='\0';// blank1
33 
34         str++;// blank2
35     }
36 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include <string.h>
 4 void sort(char *name[], int n);
 5 
 6 int main() {
 7     char *course[4] = {"C Program",
 8                        "C++ Object Oriented Program",
 9                        "Operating System",
10                        "Data Structure and Algorithms"};
11     int i;
12 
13     sort(course, 4);
14 
15     for (i = 0; i < 4; i++)
16         printf("%s\n", course[i]);
17 
18 
19     system("pause");
20     return 0;
21 }
22 
23 void sort(char *name[], int n) {
24     int i, j;
25     char *tmp;
26 
27     for (i = 0; i < n - 1; ++i)
28         for (j = 0; j < n - 1 - i; ++j)
29             if (strcmp(name[j], name[j + 1]) > 0) {
30                 tmp = name[j];
31                 name[j] = name[j + 1];
32                 name[j + 1] = tmp;
33             }
34 }

 1 #include <stdio.h>
 2 #include <string.h>
 3 void sort(char *name[], int n);
 4 
 5 int main() {
 6     char *course[4] = {"C Program",
 7                        "C++ Object Oriented Program",
 8                        "Operating System",
 9                        "Data Structure and Algorithms"};
10     int i;
11 
12     sort(course, 4);
13     for (i = 0; i < 4; i++)
14         printf("%s\n", course[i]);
15 
16     return 0;
17 }
18 
19 void sort(char *name[], int n) {
20     int i, j, k;
21     char *tmp;
22 
23     for (i = 0; i < n - 1; i++) {
24         k = i;
25         for (j = i + 1; j < n; j++)
26             if (strcmp(name[j], name[k]) < 0)
27                 k = j;
28 
29         if (k != i) {
30             tmp = name[i];
31             name[i] = name[k];
32             name[k] = tmp;
33         }
34     }
35 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #include <string.h>
 4 #define N 5
 5 
 6 int check_id(char *str); // 函数声明
 7 
 8 int main() {
 9     char *pid[N] = {"31010120000721656X",
10                     "330106199609203301",
11                     "53010220051126571",
12                     "510104199211197977",
13                     "53010220051126133Y"};
14     int i;
15 
16     for (i = 0; i < N; ++i)
17         if (check_id(pid[i])) // 函数调用
18             printf("%s\tTrue\n", pid[i]);
19         else
20             printf("%s\tFalse\n", pid[i]);
21 
22 
23     system("pause");
24     return 0;
25 }
26 
27 // 函数定义
28 // 功能: 检查指针str指向的身份证号码串形式上是否合法。
29 // 形式合法，返回1，否则，返回0
30 int check_id(char *str) 
31 {
32     int i=strlen(str);
33     int flag=1;
34     if(i!=18)
35         return 0;
36     else
37     {
38         while(*str!='\0')
39         {
40             if((*str<'0'||*str>'9')&&*str!='X')
41             {flag=0;break;}
42             str++;
43         }
44         return flag;
45     }
46 }

 1 #include<stdio.h>
 2 #include<stdlib.h>
 3 #define N 80
 4 void encoder(char *str); // 函数声明
 5 void decoder(char *str); // 函数声明
 6 
 7 int main() {
 8     char words[N];
 9 
10     printf("输入英文文本: ");
11     gets(words);
12 
13     printf("编码后的英文文本: ");
14     encoder(words); // 函数调用
15     printf("%s\n", words);
16 
17     printf("对编码后的英文文本解码: ");
18     decoder(words); // 函数调用
19     printf("%s\n", words);
20     system("pause");
21     return 0;
22 }
23 
24 /*函数定义
25 功能：对s指向的字符串进行编码处理
26 编码规则：
27 对于a~z或A~Z之间的字母字符，用其后的字符替换; 其中，z用a替换，Z用A替换
28 其它非字母字符，保持不变
29 */
30 void encoder(char *str) 
31 {
32     while(*str)
33     {
34         if(*str=='z'||*str=='Z')
35         {
36             *str=*str-26;
37         }
38         if((*str<'z'&&*str>='a')||(*str<'Z'&&*str>='A'))
39             *str=*str+1;
40         str++;
41     }
42 }
43 
44 /*函数定义
45 功能：对s指向的字符串进行解码处理
46 解码规则：
47 对于a~z或A~Z之间的字母字符，用其前面的字符替换; 其中，a用z替换，A用Z替换
48 其它非字母字符，保持不变
49 */
50 void decoder(char *str) 
51 {
52     while(*str)
53     {
54         if(*str=='a'||*str=='A')
55         {
56             *str=*str+26;
57         }
58         if((*str>'a'&&*str<='z')||(*str>'A'&&*str<='Z'))
59             *str=*str-1;
60         str++;
61     }
62 }