task1-1
#include <stdio.h> #define N 5 #define M 80 typedef struct { char name[M];//书名 char author[M]; }Book; int main() { Book x[N]={{"一九八四","乔治.奥威尔"}, {"美丽新世界","赫胥黎"}, {"昨日的世界","斯蒂芬.茨威格"}, {"历历十五年","黄仁宇"}, {"一只特立独行的猪","王小波"}}; int i; FILE *fp; //打开文本文件date1.txt fp=fopen("deta1.txt","w"); //打开失败输出信息并返回 if(fp==NULL) { printf("fail to open file\n"); return 1; } //将结构体数组x中的图书信息写到fp指向的文件data1.txt // 同时也输出到屏幕上 for(i=0;i<N;++i) { fprintf(fp,"%-20s %-20s\n",x[i].name,x[i].author); printf(fp,"%-20s %-20s\n",x[i].name,x[i].author); } fclose(fp); return 0; }
task1-2
// 从文本文件data1.txt中读取图书信息，并打印输出到屏幕 #include <stdio.h> #define N 5 #define M 80 typedef struct { char name[M]; // 书名 char author[M]; // 作者 }Book; int main() { Book x[N]; int i; FILE *fp; // 以读的方式打开文本文件data1.txt fp = fopen("data1.txt", "r"); // 如果打开文件失败，输出提示信息并返回 if(fp == NULL) { printf("fail to open file\n"); return 1; } // 从fp指向的文件data1.txt中读取信息到结构体数组x // 同时，把x的内容输出到屏幕上 for(i=0; i<N; ++i) { fscanf(fp, "%s %s\n", x[i].name, x[i].author); printf("%-20s %-20s\n", x[i].name, x[i].author); } fclose(fp); return 0;}
因为数组名本身就是首地址
task2-1
// 将图书信息以数据块方式写入二进制文件data2.dat #include <stdio.h> #define N 5 #define M 80 typedef struct { char name[M]; // 书名 char author[M]; // 作者 }Book; int main() { Book x[N] = { {"一九八四", "乔治.奥威尔"}, {"美丽新世界", "赫胥黎"}, {"昨日的世界", "斯蒂芬.茨威格"}, {"万历十五年", "黄仁宇"}, {"一只特立独行的猪", "王小波"} }; int i; FILE *fp; // 以写的方式打开二进制文件data2.dat fp = fopen("data2.dat", "wb"); // 如果打开文件失败，输出提示信息并返回 if(fp == NULL) { printf("fail to open file\n"); return 1; } // 将结构体数组x中的图书信息写以数据块方式写入文件 // 把从地址x处开始sizeof(Book)×N个字节大小的数据块写入fp指向的文件 fwrite(x, sizeof(Book), N, fp); fclose(fp); return 0; }
task2-2
#include <stdio.h> #define N 5 #define M 80 typedef struct { char name[M]; char author[M]; }Book; int main() { Book x[N]; int i; FILE *fp; fp=fopen("data2.dat","rb"); if(fp == NULL) { printf("fail to open file\n"); return 1; } fread(x, sizeof(Book), N, fp); for(i=0;i<N;++i) printf("%-20s%-20s\n",x[i].name,x[i].author); fclose(fp); return 0; }
task3-1
#include <stdio.h> int main() { FILE *fin, *fout; char ch; fin=fopen("data3_1.txt","r"); if(fin==NULL) { printf("fail to open date3_1.txt\n"); return 1; } fout=fopen("date3_2.txt","w"); if(fin==NULL) { printf("fail to open date3_2.txt\n"); return 1; } while(!feof(fin)) { ch=fgetc(fin);//fin指向的文件1_txt读取单个字符 if(ch>='a'&&ch<='z') ch-=32;//如果是小写的字母换成大写 fputc(ch,fout); } fclose(fin); fclose(fout); return 0; }
task4
#include <stdio.h> #define N 5 typedef struct { long no; char name[20]; int score; } STU; int findMinlist(STU s[], int n, STU t[]); int main() { STU stu[N], minlist[N]; int count, i; FILE *fin, *fout; // 从文件中读取学生数据到结构体数组stu中，并在屏幕上打印输出 fin = fopen("data4_1.txt", "r"); if(fin == NULL) { printf("fail to open file\n"); return 1; } for(i=0; i<N; ++i) { fscanf(fin, "%ld %s %d", &stu[i].no, stu[i].name, &stu[i].score); printf("%ld %s %d\n", stu[i].no, stu[i].name, stu[i].score); } fclose(fin); // 查找最低分学生信息并统计最低分学生人数 count = findMinlist(stu, N, minlist); // 将最低分学生信息在屏幕上打印输出 printf("\n一共有%d个最低分,信息如下: \n", count); for(i=0; i<count; ++i) printf("%ld %s %d\n", minlist[i].no, minlist[i].name, minlist[i].score); // 将最低分学生信息写入文件data4_2.txt fout = fopen("data4_2.txt", "w"); if(fout == NULL) { printf("fail to open file\n"); return 1; } for(i=0; i<count; ++i) fprintf(fout, "%ld %s %d\n", minlist[i].no, minlist[i].name, minlist[i].score); fclose(fout); return 0; } int findMinlist(STU s[], int n, STU t[]) { int i, k, min_score; // 找最低分 min_score = s[0].score; for(i=1; i<n; ++i) if(s[i].score < min_score) min_score = s[i].score; // 统计最低分人数，把最低分学生信息保存到数组t k = 0; for(i=0; i<n; ++i) if(s[i].score == min_score) { t[k] = s[i]; ++k; } return k; }
task3-2
#include <stdio.h> int main() { FILE *fin; char ch; int i=0; // 以只读、文本方式打开文件data3_1.txt fin = fopen("data3_1.txt", "r"); // 如果打开失败，输出提示信息并返回 if(fin == NULL) { printf("fail to open data3_1.txt\n"); return 1; } while(!feof(fin)) {ch=fgetc(fin); if(ch!=NULL&&ch!=' '&&ch!='\n'&&ch!='\0'&&ch!='\t') i++; } printf("date3.1txt中共包含字符数：%d",i); return 0; }//
task5
#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; char level[10]; } STU; // 函数声明 void input(STU s[], int n); void output(STU s[], int n); void process(STU s[], int n); int main() { STU stu[N]; printf("从文件读入%d个考生信息: 准考证号，姓名，客观题得分(<=40)，操作题得分(<=60)\n", N); input(stu, N); printf("\n对考生信息进行处理: 计算总分，确定等级\n"); process(stu, N); printf("\n打印考生完整信息, 并保存到文件中"); output(stu, N); return 0; } // 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 input(STU s[], 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", &s[i].id, s[i].name, &s[i].objective, &s[i].subjective); } fclose(fin); } //输出考生完整信息: 准考证号，姓名，客观题得分，操作题得分，总分，等级 // 不仅输出到屏幕上，还写到文本文件result.txt中 void output(STU s[], int n) { FILE *fout; int i; // 输出到屏幕 printf("\n"); 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等级\n"); for (i = 0; i < n; i++) printf("%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].level); // 保存到文件 fout = fopen("result.txt", "w"); if (!fout) { printf("fail to open or create result.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等级\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].level); fclose(fout); } // 对考生信息进行处理：计算总分，排序，确定等级 void process(STU s[], int n) { int i,j; int t,min; for(i=0;i<n;i++) s[i].sum=s[i].objective+s[i].subjective; for(i=0;i<n-1;i++) for(j=0;j<n-i-1;j++) if(s[j].sum<s[j+1].sum) {t=s[j].sum; s[j].sum=s[j+1].sum; s[j+1].sum=t; } for(i=0;i<n;i++) { if (i == 0) strcpy(s[i].level, "优秀"); else if (i >= 1 && i <= 4) strcpy(s[i].level, "合格"); else strcpy(s[i].level, "不合格"); }}
task6
#include<stdio.h> #include<string.h> #include<stdlib.h> #define N 80 typedef struct { long int xuehao; char name[20]; char grade[80]; }STU; int main() { STU s[80]; STU a[5]; int i; FILE *fp1,*fp2; fp1 = fopen("list.txt", "r"); fp2=fopen("lucky.txt","w+"); if (fp1 == NULL) { printf("fail to open file\n"); exit(0); } for(i=0;i<N;i++) fscanf(fp1,"%d %s %s",&s[i].xuehao,s[i].name,s[i].grade); for(i=0;i<5;i++) { int t; t=rand()%80; printf("%-20d %-20s %-20s\n",s[t].xuehao,s[t].name,s[t].grade); fprintf(fp2,"%-20d %-20s %-20s\n",a[t].xuehao,a[t].name,a[t].grade); } fclose(fp1); fclose(fp2); return 0; }
