实验4
#include<stdio.h> int main() { FILE *fp; fp=fopen("d:\\data4.txt","r"); if(fp==NULL){ printf("fail to open file.\n"); return 1; } char ch; int cnt=0; while((ch=fgetc(fp))!=EOF){ if(ch==' '||ch=='\n') continue; cnt++; } printf("data4.txt中共包含字符数(不计空白格):%d\n",cnt); fclose(fp); return 0; }
实验5
#include <stdio.h> #include <string.h> #include <stdlib.h> #define N 10 typedef struct { long int id; char name[20]; float objective; // 客观题得分 float subjective; // 操作题得分 float sum; // 总分 char ans[10]; // 考试结果 } STU; // 函数声明 void finput(STU st[], int n); void foutput(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); finput(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); // 输出到屏幕 foutput(stu, N); // 输出到文件 pass_rate = 1.0 * cnt / N; printf("\n本次等级考试通过率: %.2f%%\n", pass_rate*100); return 0; } // 把通过考试的考生完整信息输出到屏幕上 // 准考证号,姓名,客观题得分,操作题得分,总分,结果 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].ans); } // 从文本文件examinee.txt读入考生信息:准考证号,姓名,客观题得分,操作题得分 void finput(STU st[], int n) { int i; FILE *fin; fin = fopen("examinee.txt", "r"); if (fin == NULL) { printf("fail to open file\n"); exit(0); } 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); } // 把通过考试的考生完整信息写入文件list_pass.txt // 准考证号,姓名,客观题得分,操作题得分,总分,结果 void foutput(STU s[], int n) { FILE *fout; int i; // 保存到文件 fout = fopen("list_pass.txt", "w"); if (!fout) { printf("fail to open or create list_pass.txt\n"); exit(0); } fprintf(fout, "准考证号\t\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++) fprintf(fout, "%ld\t\t%s\t%.2f\t\t%.2f\t\t%.2f\t\t%s\n", s[i].id, s[i].name, s[i].objective, s[i].subjective, s[i].sum, s[i].ans); fclose(fout); } // 对考生信息进行处理:计算每位考生考试总分、结果;统计考试通过的人数 int process(STU st[], int n, STU st_pass[]) { int count = 0, i, j; STU t; FILE* fout; fout = fopen("list_pass.txt", "r+"); for (i = 0; i < n; i++) st[i].sum = st[i].objective + st[i].subjective; for(i = 0,j = 0;i < n;i++) { if(st[i].sum>=60) { strcpy(st[i].ans, "pass"); count++; st_pass[j++] = st[i]; } else strcpy(st[i].ans, "fail"); } fclose(fout); return count; }
实验6
#include<stdio.h> #include<stdlib.h> #include<time.h> typedef struct{ long id; char name[20]; char ban[40]; }xx; int main() { xx a[5],x[80]; int i,n; FILE *fp,*fps; fp = fopen("d:\\date\\list.txt","r"); if(fp==NULL) { printf("fail to open\n"); return 1; } srand((double)time(NULL)); for(i=0;i<80;i++) fscanf(fp,"%ld%s%s",&x[i].id,x[i].name,x[i].ban); for(i=0;i<5;i++) { n=rand()%(204942080-204942001+1); a[i]=x[n]; printf("%-20ld%-20s%-20s\n",a[i].id,a[i].name,a[i].ban); } fclose(fp); fps=fopen ("lucky.txt","w"); if(fps==NULL) { printf("fail to open\n"); return 1; } for(i=0;i<5;i++) fprintf(fps,"%-20ld%-20s%-20s\n",a[i].id,a[i].name,a[i].ban); fclose(fps); return 0; }