上机实验作业5
task 1-1
#include <stdio.h> #define N 5 #define M 80 typedef struct { char name[M]; 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"}, {"万历十五年", "黄仁宇"}, {"一只特立独行的猪", "王小波"} }; int i; FILE *fp; fp=fopen("data1.txt","w"); if(fp==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; }
task 1-2
#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("data1.txt","r"); if(fp==NULL) { printf("fail to open file\n"); return 1; } 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; }
字符型数组其数组名本身就代表地址，所以不用加地址符号。
task 2-1
#include <stdio.h> #define N 5 #define M 80 typedef struct { char name[M]; 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"}, {"万历十五年", "黄仁宇"}, {"一只特立独行的猪", "王小波"} }; 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; }
是，否
task 2-2
#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; }
task 3-2
#include <stdio.h> int main() { FILE *fin; char ch; int i=0; fin = fopen("data3_1.txt", "r"); if(fin == NULL) { printf("fail to open data3_1.txt\n"); return 1; } while( !feof(fin) ) { ch = fgetc(fin); if(ch!='\0' && ch!=' ' && ch!='\t') i=i+1; } fclose(fin); printf("data3-1.txt中共包含字符数：%d",i); return 0; }
task 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; 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,k; STU temp; for(i=0;i<n;++i) s[i].sum=s[i].objective+s[i].subjective; for(i=0;i<n;i++) { for(k=0;k<n-1-i;k++) { if(s[k].sum<s[k+1].sum) { temp=s[k]; s[k]=s[k+1]; s[k+1]=temp; } } } j = n/10; for(i=0;i<j;i++) { strcpy(s[i].level,"优秀"); } k = n/2; for(i=j;i<k;++i) { strcpy(s[i].level,"合格"); } for(i=k;i<n;i++) { strcpy(s[i].level,"不合格"); } }
task 6
#include <stdio.h> #include <stdlib.h> #include <time.h> #define N 81 #define M 5 typedef struct { long int id; char name[20]; char banji[60]; }STU; int main() { int i,j; STU x[N],ran[M]; FILE *fin,*fout; fin = fopen("list.txt","r"); if(fin == NULL) { printf("fail to open list.txt\n"); return 1; } for(i=1;i<=N;i++) { fscanf(fin, "%ld %s %s", &x[i].id, x[i].name, x[i].banji); } fclose(fin); srand(time(0)); j = rand()%(80)+1; for(i=0;i<M;i++) { ran[i] = x[j]; j = rand()%(80)+1; } fout = fopen("lucky.txt", "w"); if(fout == NULL) { printf("fail to open file\n"); return 1; } for(i=0;i<M;i++) { fprintf(fout, "%ld %s %s\n", ran[i].id, ran[i].name, ran[i].banji); printf("%ld %s %s\n", ran[i].id, ran[i].name, ran[i].banji); } fclose(fout); return 0; }
