实验5

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

问题1；找到一组数中最大最小数
问题2；指向x[0]的数值

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

问题1；找到一组数据中最大值
问题2；可以

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

问题1；s1是20；strlen统计s1长度

问题2；不能，数组不能直接赋值；