实验七
task1_1
#include<stdio.h> #define N 7 #define M 80 typedef struct{ char name[M]; char author[M]; }Book; int main(){ Book x[N] ={{"《雕塑家》","斯科特·麦克劳德"}, {"《灯塔》","克里斯多夫·夏布特"}, {"《五号屠宰场》","库尔特·冯内古特"}, {"《出卖月亮的人》","罗伯特·海因莱茵"}, {"《大地之上》","罗欣顿·米斯特里"}, {"《上学记》","何兆武"}, {"《命运》","蔡崇达"}}; int i; FILE *fp; fp=fopen("data1.txt","w"); if(fopen==NULL) { printf("fail to open file\n"); return 1; } for(i=0;i<N;++i){ fprintf(fp,"%-20s %-20s\n",x[i].name,x[i].author); printf("%-20s %-20s\n",x[i].name,x[i].author); } fclose(fp); return 0; }
task1_2
#include<stdio.h> #define N 10 #define M 80 typedef struct{ char name[M]; char author[M]; }Book; int main(){ Book x[N]; int i,n; FILE *fp; fp=fopen("data1.txt","r"); if(fp==NULL){ printf("fail to open file\n"); return 1; } i=0; while(!feof(fp)){ fscanf(fp,"%s%s",x[i].name,x[i].author); ++i; } n=i-1; for(i=0;i<N;++i) printf("%d. %-20s%-20s\n",i+1,x[i].name,x[i].author); fclose(fp); return 0; }
将n=i-1换成n=i后运行结果
原因：n此时等于9，多读了一个没有的信息。
task2_1
#include <stdio.h> #define N 7 #define M 80 typedef struct { char name[M]; char author[M]; } Book; int main() { Book x[N] = {{"《雕塑家》", "斯科特.麦克劳德"}, {"《灯塔》", "克里斯多夫.夏布特"}, {"《五号屠宰场》", "库尔特.冯内古特"}, {"《出卖月亮的人》", "罗伯特.海因莱茵"}, {"《大地之上》", "罗欣顿·米斯特里"}, {"《上学记》", "何兆武"}, {"《命运》", "蔡崇达"} }; int i; FILE *fp; fp = fopen("data2.dat", "wb"); if(fp == NULL) { printf("fail to open file\n"); return 1; } fwrite(x, sizeof(Book), N, fp); fclose(fp); return 0;
}
task2_2
#include<stdio.h> #define N 7 #define M 80 typedef struct{ char name[M]; char author[M]; }Book; int main(){ Book x[N]; int i,n; 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("%d. %-20s%-20s\n",i+1,x[i].name,x[i].author); fclose(fp); return 0; }
task3_1
#include<stdio.h> #define N 5 #define M 80 int main(){ char songs[N][M]={"working\'s Blues", "Everything will Flow", "streets of London", "perfect Day", "philadelphia"}; int i; FILE *fp; fp=fopen("data3.txt","w"); if(fp==NULL){ printf("fail to open file\n"); return 1; } for(i=0;i<N;++i){ fputs(songs[i],fp); fputs("\n",fp); } fclose(fp); return 0; }
原因：反斜杠在c语言中是转义字符，所以没有输出
task3_2
#include<stdio.h> #define N 5 #define M 80 int main(){ char songs[N][M]; int i; FILE *fp; fp=fopen("data3.txt","r"); if(fp==NULL){ printf("fail to open file\n"); return 1; } for(i=0;i<N;++i){ fgets(songs[i],80,fp); } for(i=0;i<N;++i){ printf("%d. %s",i+1,songs[i]);} fclose(fp); return 0;}
task3_3
#include<stdio.h> #define N 5 #define M 80 int main(){ char ch; FILE *fp; fp=fopen("data3.txt","r"); if(fp==NULL){ printf("fail to open file\n"); return 1; } ch=fgetc(fp); while(ch!=EOF){ putchar(ch); ch=fgetc(fp); } fclose(fp); return 0;}
task4
#include<stdio.h> int main(){ char ch; int i=0; FILE *fp; fp=fopen("data4.txt","r"); if(fp==NULL){ printf("fail to open file\n"); return 1;} ch=fgetc(fp); while(ch!=EOF){ if(ch!=' '&&ch!='\n') i++; ch=fgetc(fp); } printf("data4.txt中共包含字符数（不计空白符）：%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) { STU ch; double sum; int i,j,q=n-1; for (i = 0; i < n; i++) s[i].sum=s[i].objective+s[i].subjective; for(i=0;i<n;++i){ for(j=0;j<n-i;++j){ if(s[j].sum<s[j+1].sum){ ch=s[j]; s[j]=s[j+1]; s[j+1]=ch; } } } for(i=0;i<q;i++){ if(i<=q*0.1) strcpy(s[i].level,"优秀"); else if(i>q*0.1&&i<q*0.5) strcpy(s[i].level,"合格"); else strcpy(s[i].level,"不合格"); } }
task6
#include<stdio.h> #include<stdlib.h> #include<time.h> #define N 100 #define M 5 typedef struct { int id; char name[20]; char group[20]; }STU; void input(STU s[], int n); void output(STU s[], int n); int main() { STU stu[N]; STU selected[M]; int i,num; input(stu, N); srand(time(0)); for (i = 0,num=0; i < M; ++i) { num = rand() % (80- 1 + 1) + 1; selected[i] = stu[num]; } output(selected, M); return 0; } void input(STU s[], int n) { int i; FILE* fin; fin = fopen("list.txt", "r"); if (fin == NULL) { printf("fail to open file\n"); exit(0); } while (!feof(fin)) { for (i = 0; i < n; i++) fscanf(fin, "%d %s %s", &s[i].id, s[i].name, &s[i].group); } fclose(fin); } void output(STU s[], int n) { FILE* fout; int i; for (i = 0; i < n; i++) printf("%d\t%s\t%s\n", s[i].id, s[i].name, s[i].group); fout = fopen("selected.txt", "w"); if (!fout) { printf("fail to open file\n"); exit(0); } for (i = 0; i < n; i++) fprintf(fout, "%d\t%s\t%s\n", s[i].id, s[i].name, &s[i].group); fclose(fout); }
