实验7

1. #include<stdio.h>
   int main(){
         FILE *data4;
         int ch,lines=0,chars=0;
         data4=fopen("data4.txt","r");
         if(!data4)
         {
               printf("Open file failed(data4.txt)");
               return 1;
         }
         while((ch=fgetc(data4))!=EOF){
               switch(ch){
               case' ':
               case'\r':
               case'\t':
                     break;
               case'\n':
                     lines++;
                     break;
               default:
                     chars++;
                     break;
               }
         }
         lines++;
         fclose(data4);
         printf("data4.txt统计结果：\n行数:%d\n字符数（不计空白符）:%d",lines,chars);
         return 0;
   }

   

   #include <stdio.h>
   #include <stdlib.h>
   #include <time.h>
   #include <string.h>
   
   #define MAX_STU 80
   
   #define DRAW_NUM 5
   
   
   typedef struct {
       char id[20];
       char name[20];
       char cls[30];
   } Student;
   
   int main()
   {
       FILE *fpIn, *fpOut;
       Student stu[MAX_STU];
       int flag[MAX_STU] = {0};
       int total = 0, i, j, randIdx, count = 0;
   
   
       fpIn = fopen("list.txt", "r");
       if(fpIn == NULL){
           printf("打开名单文件失败！\n");
           return 1;
       }
       while(fscanf(fpIn, "%s %s %s", stu[total].id, stu[total].name, stu[total].cls) != EOF){
           total++;
       }
       fclose(fpIn);
   
   
       srand((unsigned)time(NULL));
       printf("----------------中奖名单----------------\n");
       while(count < DRAW_NUM){
           randIdx = rand() % total;
           if(flag[randIdx] == 0){
               flag[randIdx] = 1;
               printf("%s %s %s\n", stu[randIdx].id, stu[randIdx].name, stu[randIdx].cls);
               count++;
           }
       }
   
   
       fpOut = fopen("20260615.txt", "w");
       for(i = 0; i < total; i++){
           if(flag[i] == 1){
               fprintf(fpOut, "%s %s %s\n", stu[i].id, stu[i].name, stu[i].cls);
           }
       }
       fclose(fpOut);
       printf("-----------------------------------------\n");
       printf("保存到文件\n");
       printf("保存文件名:20260615.txt\n");
   
       return 0;
   }

   

    

   #define _CRT_SECURE_NO_WARNINGS
   #include <stdio.h>
   #include <stdlib.h>
   #include <time.h>
   #include <string.h>
   #include <windows.h>
   
   #define MAX_STUDENT 80
   #define WIN_COUNT 5
   
   typedef struct {
       long id;
       char name[20];
       char className[40];
   } Student;
   
   int main(void)
   {
       SetConsoleOutputCP(936);
       Student stuArr[MAX_STUDENT];
       int total = 0;
       int selected[MAX_STUDENT] = {0};
       Student winner[WIN_COUNT];
       char saveFileName[50];
       FILE *fpRead, *fpWrite;
   
       fpRead = fopen("list.txt", "r");
       if (fpRead == NULL)
       {
           printf("Error: Cannot open list.txt\n");
           system("pause");
           return 1;
       }
   
       while (total < MAX_STUDENT && fscanf(fpRead, "%ld %s ", &stuArr[total].id, stuArr[total].name) == 2)
       {
           fgets(stuArr[total].className, sizeof(stuArr[total].className), fpRead);
           stuArr[total].className[strcspn(stuArr[total].className, "\n")] = '\0';
           total++;
       }
       fclose(fpRead);
   
       if(total < WIN_COUNT)
       {
           printf("Insufficient number of students\n");
           system("pause");
           return 1;
       }
   
       srand((unsigned)time(NULL));
       for(int i = 0; i < WIN_COUNT; )
       {
           int idx = rand() % total;
           if(!selected[idx])
           {
               selected[idx] = 1;
               winner[i++] = stuArr[idx];
           }
       }
   
       printf("===== Winner List =====\n");
       printf("ID\t\tName\t\tClass\n");
       for(int i = 0; i < WIN_COUNT; i++)
       {
           printf("%ld\t%s\t%s\n",winner[i].id,winner[i].name,winner[i].className);
       }
   
       printf("\nEnter output filename:");
       scanf("%s", saveFileName);
   
       fpWrite = fopen(saveFileName, "w");
       fprintf(fpWrite, "Winner List\n");
       fprintf(fpWrite, "ID\tName\tClass\n");
       for(int i = 0; i < WIN_COUNT; i++)
       {
           fprintf(fpWrite, "%ld\t%s\t%s\n",winner[i].id,winner[i].name,winner[i].className);
       }
       fclose(fpWrite);
       printf("Data saved to %s successfully\n", saveFileName);
   
       system("pause");
       return 0;
   }