【C语言程序设计第四版】练习12-6

实数取整写入文件

#include <stdio.h>
#include <stdlib.h>
#define MAXN 300


int main(void){
    
    int i,j;
    FILE *fp, *fp1;
    double nums[MAXN];
    
    
    
    if ((fp=fopen("f1.txt", "r")) == NULL) {
        printf("File open errpr!\n");
        exit(0);
    }
    
    if ((fp1=fopen("f2.txt", "w")) == NULL) {
        printf("File open errpr!\n");
        exit(0);
    }
    
    
    i = 0;
    while (!feof(fp)) {
        fscanf(fp, "%lf", &nums[i]);
        i++;
    }

    for (j=0; j<i-1; j++) {
        fprintf(fp1, "%.0f ", nums[j]);
    }
    
    
    if ((fclose(fp))) {
        printf("Can not close the file!\n");
        exit(0);
    }
    
    if ((fclose(fp1))) {
        printf("Can not close the file!\n");
        exit(0);
    }

    return 0;
}

 

改进版本,不需要定义数组

#include <stdio.h>
#include <stdlib.h>
#define MAXN 300


int main(void){
    
    int i,j;
    FILE *fp, *fp1;
    double nums;
    
    
    
    if ((fp=fopen("f1.txt", "r")) == NULL) {
        printf("File open errpr!\n");
        exit(0);
    }
    
    if ((fp1=fopen("f2.txt", "w")) == NULL) {
        printf("File open errpr!\n");
        exit(0);
    }
    
    
    fscanf(fp, "%lf", &nums);
    while (!feof(fp)) {
        fprintf(fp1, "%.0f ", nums);
        fscanf(fp, "%lf", &nums);
    }
    
    if ((fclose(fp))) {
        printf("Can not close the file!\n");
        exit(0);
    }
    
    if ((fclose(fp1))) {
        printf("Can not close the file!\n");
        exit(0);
    }

    return 0;
}