#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; }
#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; }
两者字符型数组，name、author就是该数组第一个数组的指针位置，不需要加&
#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; }
#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; }
1、生成了；2、可以打开。
#include<stdio.h> int main() { FILE *fin; char ch; int c=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>=33&&ch<=122) c+=1; } printf("data3_1.txt中共包含字符数：%d",c); return 0; }
#include<stdio.h> #include<string.h> #include<stdlib.h> #define N 10 typedef struct { long int id; char name[20]; float objective; float subjective; float sum; char level[10]; }STU; 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; } 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); } void output(STU s[],int n) { FILE *fout; int i; 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); 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); } void process(STU s[], int n) { int i,j,k; float Y,L; STU temp; for(i=0;i<n;i++) s[i].sum=s[i].objective+s[i].subjective; for(i=1;i<n;i++) for(j=0;j<i;j++) { if(s[i].sum>s[j].sum) { k=j; temp=s[i]; for(j=i-1;j>=k;j--) s[j+1]=s[j]; s[k]=temp; } } Y=s[(int)(n*0.1-1)].sum; L=s[(int)(n*0.5-1)].sum; for(i=0;i<n;i++) if(s[i].sum>=Y) strcpy(s[i].level,"优秀"); else if(s[i].sum>=L) strcpy(s[i].level,"合格"); else strcpy(s[i].level,"不合格"); }
#include <stdio.h> #include <stdlib.h> #include <time.h> #define M 80 #define N 5 typedef struct { long int id; char name[20]; char classes[80]; int target; } STU; void input(STU s[], int n); void random(STU s[],STU lucky[],int m,int n); void output(STU lucky[], int n); int main() { STU stu[M]; STU lucky[N]; input(stu, M); random(stu,lucky,M,N); output(lucky,N); 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, "%ld %s %s", &s[i].id, s[i].name, s[i].classes); } fclose(fin); } void random(STU s[],STU lucky[],int m,int n) { int k = 0; srand(time(NULL)); while (k < n) { int i = rand()%m + 1; lucky[k] = s[i]; k++; } } void output(STU lucky[], int n) { for (int i = 0; i < 5; i++) printf("%ld\t%-10s %-10s\n", lucky[i].id, lucky[i].name, lucky[i].classes); FILE *fout; fout = fopen("lucky.txt", "w"); for (int i = 0; i < n; i++) fprintf(fout, "%ld\t%-10s %-10s\n", lucky[i].id, lucky[i].name, lucky[i].classes); fclose(fout); }
#include <stdio.h> #include <stdlib.h> #include <time.h> #define M 80 #define N 5 typedef struct { long int id; char name[20]; char classes[80]; int target; } STU; void input(STU s[], int n); void random(STU s[],STU lucky[],int m,int n); void output(STU lucky[], int n); int main() { STU stu[M]; STU lucky[N]; input(stu, M); random(stu,lucky,M,N); output(lucky,N); 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, "%ld %s %s", &s[i].id, s[i].name, s[i].classes); } fclose(fin); } void random(STU s[],STU lucky[],int m,int n) { int x[m]; int k = 0; srand(time(NULL)); while (k < n) { int i = rand()%m + 1; if(x[i] == 1) continue; lucky[k] = s[i]; x[i] = 1; k++; } } void output(STU lucky[], int n) { for (int i = 0; i < 5; i++) printf("%ld\t%-10s %-10s\n", lucky[i].id, lucky[i].name, lucky[i].classes); FILE *fout; fout = fopen("lucky2.txt", "w"); for (int i = 0; i < n; i++) fprintf(fout, "%ld\t%-10s %-10s\n", lucky[i].id, lucky[i].name, lucky[i].classes); fclose(fout); }
