实验七
任务四
源代码:
#include<stdio.h> int main() { FILE* fp; fp = fopen("data4.txt", "r"); if(fp == NULL) { perror("Error opening file"); return 1; } char ch; int a = 1, b = 0; while ((ch = fgetc(fp)) != EOF) { if (ch == '\n') { a++; } if (ch != ' '&&ch!='\n'&&ch!='\t') { b++; } } fclose(fp); printf("data4.txt统计结果:\n行数:%d\n字符数(不计空白符):%d", a, b); }
运行结果:
任务五
源代码:
#include <stdio.h> #include <string.h> #define N 10 typedef struct { long id; char name[20]; float objective; float subjective; float sum; char result[10]; } STU; void read(STU st[], int n); void write(STU st[], int n); void output(STU st[], int n); int process(STU st[], int n, STU st_pass[]); int main() { STU stu[N], stu_pass[N]; int cnt; double pass_rate; printf("从文件读入%d个考生信息...\n", N); read(stu, N); printf("\n对考生成绩进行统计...\n"); cnt = process(stu, N, stu_pass); printf("\n通过考试的名单:\n"); output(stu, N); write(stu, N); pass_rate = 1.0 * cnt / N; printf("\n本次等级考试通过率: %.2f%%\n", pass_rate*100); return 0; } void output(STU st[], int n) { int i; printf("准考证号\t姓名\t客观题得分\t操作题得分\t总分\t\t结果\n"); for (i = 0; i < n; i++) printf("%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n", st[i].id, st[i].name, st[i].objective, st[i].subjective, st[i].sum, st[i].result); } void read(STU st[], int n) { int i; FILE *fin; fin = fopen("examinee.txt", "r"); if (!fin) { printf("fail to open file\n"); return; } while (!feof(fin)) { for (i = 0; i < n; i++) fscanf(fin, "%ld %s %f %f", &st[i].id, st[i].name, &st[i].objective, &st[i].subjective); } fclose(fin); } void write(STU st[], int n) { int i; float sum; FILE *fout = fopen("list_pass.txt","w"); if(fout == NULL) { perror("Error opening file"); return; } for (i = 0; i < n; i++){ sum = st[i].objective + st[i].subjective; char result[10]; if (sum >= 60) { sprintf(result, "Pass"); } else { sprintf(result, "Fail"); } fprintf(fout, "%ld %s %.2f %.2f %.2f %s\n", st[i].id, st[i].name, st[i].objective, st[i].subjective, sum, result); } fclose(fout); } int process(STU st[], int n, STU st_pass[]) { int pass_count = 0; int i; for (i = 0; i < n; i++) { st[i].sum = st[i].objective + st[i].subjective; if (st[i].sum >= 60) { strcpy(st[i].result, "合格"); st_pass[pass_count] = st[i]; pass_count++; } else { strcpy(st[i].result, "不合格"); } } return pass_count; }
运行结果:
任务六
源代码:
#include <stdio.h> #include <stdlib.h> #include <time.h> #include <string.h> void readStudentList(char students[][200], int *count) { FILE *fp; fp = fopen("list.txt", "r"); if (fp == NULL) { printf("无法打开文件\n"); return; } *count = 0; while (fgets(students[*count], 200, fp)!= NULL) { (*count)++; } fclose(fp); } void randomSelectStudents(char students[][200], char selected[][200], int count) { int i; int selectedCount = 0; srand((unsigned int)time(NULL)); while (selectedCount < 5) { int index = rand() % count; int found = 0; for (i = 0; i < selectedCount; i++) { if (strcmp(students[index], selected[i]) == 0) { found = 1; break; } } if (!found) { strcpy(selected[selectedCount], students[index]); selectedCount++; } } } void displayAndWrite(char selected[][200]) { int i; printf("----------随机抽点名单----------\n"); for (i = 0; i < 5; i++) { printf("%s", selected[i]); } char fileName[100]; printf("----------保存到文件----------\n"); printf("请输入文件名:"); scanf("%s", fileName); FILE *fp = fopen(fileName, "w"); if (fp == NULL) { printf("无法创建文件\n"); return; } for (i = 0; i < 5; i++) { fputs(selected[i], fp); } fclose(fp); printf("保存成功!\n"); } int main() { char students[80][200]; char selected[5][200]; int count; readStudentList(students, &count); randomSelectStudents(students, selected, count); displayAndWrite(selected); return 0; }
运行结果: