如何从文件中读取数字并将它们分配给它们的实际含义

Question

写一个C程序来

1. 计算安大略省一系列湖滩的大肠杆菌平均水平
2. 决定打开或关闭海滩
3. 为数据文件中包含的所有湖泊和海滩生成一份报告。

对于每个海滩，文件中有一行数据，以下字段由空格分隔 - 湖 ID（整数）、海滩编号（整数）、采样数（整数）和一个实数（双精度）采样代表 100 毫升水中的生物数量。

湖桌

1: Ontario        
2: Erie    
3: Huron       
4: Muskoka   
5: Simcoe

沙滩桌

100: Kew Beach       
101: Sunnyside Beach  
103: Sandbanks   
201: Port Dover  
202: Port Burwell  
203: Crystal Beach   
301: Goderich  
302: Sauble Beach    
303: Kincardine   
401: Muskoka Beach   
501: Sibbald Point   

这是文件数据：

1 100 12 47.7 52.2 45.5 78.7 45.5 33.2 50.4 60.2 48.9 43.3 49.9 50.6     
1 101 9 75.5 53.2 65.1 81.1 44.1 42.2 41.1 39.7 51.1      
2 201 3 56.6 49.7 45.5     
2 202 2 44.4 66.6          
5 501 4 55.5 34.4 66.6 22.2     
4 401 4 33.3 44.4 55.5 66.6        
3 301 3 50.0 51.1 49.8       
3 302 4 77.7 66.6 22.2 33.3      
3 303 3 55.5 55.5 44.0      
1 103 1 13.3    

我知道如何编写代码和语句，但我不知道如何让程序读取文件以及我将如何分配那个特定的数字是安大略湖，或者如何让程序对样本进行平均, 我第一次编程才 2 个月，所以请多多包涵。

Answer 1

您可以在文件中写入块结构，以将数据保存为二进制。

用于创建结构

struct Lake_table {
    int id;
    char name[length];
};

struct Beach_table {
    int samplings;
    char name[length]
    double samplings_ml;

};

以这种方式用数据初始化结构！

struct Lake_table lakes[] =  {
{1,"Ontario"}
{2,"Erie"}
{3,"Huron"}
{4,"Muskoka"}
{5,"Simcoe"}
};

struct Beach_table beaches[] = {
{100,"Kew Beach",0.0}
{101,"Sunnyside Beach",0.0}
{103,"Sandbanks",0.0}
{201,"Port Dover",0.0}
{202,"Port Burwell",0.0}
{203,"Crystal Beach",0.0}
{301,"Goderich",0.0}
{302,"Sauble Beach",0.0}
{303,"Kincardine",0.0}
{401,"Muskoka Beach",0.0}
{501,"Sibbald Point",0.0}
};

要保存您的结构，请执行此操作！

FILE *file;
const char file_name[] =  "filename.dat";
file = fopen(file_name,"wb");
if (file != EOF) {
    fwrite(beaches,sizeof(struct Beach_table),length,file);

}

让你的结构去做吧！

struct Beach_table beaches;
FILE *file;
    const char file_name[] =  "filename.dat";
    file = fopen(file_name,"rb");
    if (file != EOF) {
        fread(beaches,sizeof(struct Beach_table),length,file);
    }

访问数据，概念与数组、指针相同。祝你好运