C文件操作

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <limits.h>
 4 
 5 int main()
 6 {
 7     int x, n=0, sum=0;
 8     int min=INT_MAX, max=INT_MIN;//click this link
 9     FILE *fin, *fout;//1、创建文件指针 
10     
11     //2、关联文件 
12     fin  = fopen("data.in", "r");
13     fout = fopen("data.out", "w");
14     
15     //3、操作文件 
16     while(fscanf(fin, "%d", &x) == 1){
17         sum += x;
18         if(x<min) min=x;
19         if(x>max) max=x;
20         n++;
21     }
22     
23     fprintf(fout, "min=%d\nmax=%d\navg=%.3lf\n",
24             min, max, (double)sum/n);
25     
26     //关闭文件 
27     fclose(fin);
28     fclose(fout);
29     
30     return 0;
31 }

 1 #include <stdio.h>
 2 #include <stdlib.h>
 3 #include <limits.h>
 4 
 5 int main() {
 6     int x,n=0,sum=0;
 7     int min=INT_MAX, max=INT_MIN;
 8 
 9     //重定义输入输出流 
10     freopen("input.txt", "r", stdin);//freopen将stdin含义改变 
11     freopen("output.txt", "w", stdout);
12 
13     while(scanf("%d",&x) == 1){
14         sum += x;
15         if(x<min)
16             min=x;
17         if(x>max)
18             max=x;
19         n++;
20     }
21     printf("min=%d\nmax=%d\navg=%.3lf\n",
22             min, max, (double)sum/n);
23     return 0;
24 }