c - 如何在循环中生成随机数，然后每 1000000 个数字将其存储在文件中？

Question

所以基本上，在无限循环中，我必须生成随机数。然后，我必须在迭代中创建文件，其中第一个循环中是 file1.txt，第二个循环中是 file2.txt 等等。我们使用文件来存储生成的每 1000000 个随机数，因此 file1.txt 存储前 100 万个数字，file2.txt 存储接下来的 100 万个数字，依此类推。但我认为我搞砸了代码。你能帮我吗？

int rng(){
    int i;
    FILE *fptr;
    int k = 0;

    char buffer[32];
    snprintf(buffer, sizeof(char) * 32, "file%i.txt", k);
    fptr=fopen(buffer, "wb");
    for(i=0; i<1000000; i++)
    {
        fprintf(fptr, "%d", (rand() * rand()) % 1000001);
    }
    fclose(fptr);
    k++;
}

Answer 1

您可以使用 while(1) 进行无限循环，然后使用简单的计数器来计算当前文件中的元素数量。

喜欢:

#include <stdio.h>

#define ELEMENTS_PER_FILE 5

int main(void) {
    unsigned k = 0;
    unsigned file_number = 1;

    printf("Open file%u.txt\n", file_number);

    while(1)
    {
        if (k == ELEMENTS_PER_FILE)
        {
            ++file_number;
            printf("Open file%u.txt\n", file_number);
            k = 0;
        }

        ++k;
        printf("   Add random number #%u to file\n", k);

    }

    return 0;
}

输出:

Open file1.txt
   Add random number #1 to file
   Add random number #2 to file
   Add random number #3 to file
   Add random number #4 to file
   Add random number #5 to file
Open file2.txt
   Add random number #1 to file
   Add random number #2 to file
   Add random number #3 to file
   Add random number #4 to file
   Add random number #5 to file
Open file3.txt
   Add random number #1 to file
   Add random number #2 to file
. . .

您需要做的就是将 printf 替换为执行打印内容的代码。

使用函数生成单个文件，可以更好地组织代码。喜欢:

#include <stdio.h>

#define ELEMENTS_PER_FILE 5
#define FILES_TO_GENERATE 3

void make_file(unsigned num)
{
    int i;
    printf("Open file%u.txt\n", num);
    for (i=1; i <= ELEMENTS_PER_FILE; ++i)
    {
        printf("   Add random number #%d to file\n", i);
    }
    printf("Close file%u.txt\n", num);
}

int main(void) {
    unsigned file_number = 1;

    while(file_number <= FILES_TO_GENERATE)  // or while(1) if you really want infinite
    {
        make_file(file_number);
        ++file_number;
    }

    return 0;
}

输出:

Open file1.txt
   Add random number #1 to file
   Add random number #2 to file
   Add random number #3 to file
   Add random number #4 to file
   Add random number #5 to file
Close file1.txt
Open file2.txt
   Add random number #1 to file
   Add random number #2 to file
   Add random number #3 to file
   Add random number #4 to file
   Add random number #5 to file
Close file2.txt
Open file3.txt
   Add random number #1 to file
   Add random number #2 to file
   Add random number #3 to file
   Add random number #4 to file
   Add random number #5 to file
Close file3.txt