从C中的字符串填充二维整数数组 [英] Populating 2d array of ints from string in C

问题描述

我想用一些数字填充一个二维整数数组.

I want to populate a 2d array of ints with some numbers.

数字采用网格格式，如下所示:

The numbers is in a grid format like the following :

08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48

我希望我的程序采用上面的字符串并将数字存储在一个 20x20 的二维整数数组中.

I want my program to take the string above and store the numbers in a 20x20 2d array of ints.

int main(void)
{

    int grid[20][20];
    for(int i = 0;i<20;i++)
    {
        for(int j = 0;j<20;j++)
        {
            grid[i][j] = //some code to populate int here
        }
    }

}

我不确定如何获取要填充的代码"

I am unsure how to get the 'code to populate'

所以我尝试使用 strtok 如下:

So I tried using strtok as below:

int main(void)
{

    char *input = "08 02 22...48";
    char *output = strtok(input," ");
    printf("%s",output);
}

但是，上面给了我一个分段错误，我不确定为什么.

However, the above is giving me a segmentation fault and I am unsure why.

我对编程非常陌生，尤其是在 C 中，我有点不确定如何将上述输入存储为二维整数数组.感谢上述任何替代路线或有关为什么我遇到分段错误的任何指导，谢谢:)

I am very new to programming, especially in C, and I am a bit unsure how to get an input like above stored as a 2d array of ints. Any alternative routes to the above or any guidance as to why I am getting segmentation faults is appreciated, thanks :)

推荐答案

strtok 给你一个分段错误的原因是你使用了一个 const char*作为输入，但 strtok 期望修改字符串(即，它在终止字符的第一个实例中插入一个 '' ).如果您只是将代码更改为

The reason that strtok is giving you a segmentation fault is that you are using a const char* as the input, but strtok expects to modify the string (namely, it inserts a '' at the first instance of the terminating character). If you just changed your code to

char input[] = "08 02 22...48";
char *output = strtok(input," ");
printf("%s",output);

您会发现它有效(因为该初始化程序创建了一个不是 const 的字符串).

You would find that it works (because that initializer creates a string that is not a const).

显然，您可以使用 sscanf 将字符串转换为数值 - 确保将要存储的位置的地址传递给它:

Obviously you can then use sscanf to convert the string to a numerical value - make sure that you pass it the address of the location where you want to store:

sscanf(output, "%d", &grid[i][j]);

您看起来知道如何将这些元素组合成一个循环结构.请注意 strtok 应该在第一次调用时使用 char* 参数，然后使用 NULL 参数...

You look like you know how to combine these elements into a loop structure. Do note that strtok should be called with a char* argument the first time, and with NULL after that...

编辑重新阅读您的问题，似乎您会从完整的代码示例中受益:

EDIT re-reading your question, it seems you would benefit from a complete code example:

#include <stdio.h>
#include <string.h>

int main(void) {

char input[]=
"08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08 "
"49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00 "
"81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65 "
"52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91 "
"22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80 "
"24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50 "
"32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70 "
"67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21 "
"24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72 "
"21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95 "
"78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92 "
"16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57 "
"86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58 "
"19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40 "
"04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66 "
"88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69 "
"04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36 "
"20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16 "
"20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54 "
"01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48";

int ii, jj;
int grid[20][20];
char *s = strtok(input, " ");

for(ii=0; ii<20; ii++){
  for(jj=0; jj<20; jj++){
    sscanf(s, "%d", &grid[ii][jj]);
    s = strtok(NULL, " ");
  }
}
for(ii=0; ii<20; ii++){
  for(jj=0; jj<20; jj++){
    printf("%02d ", grid[ii][jj]);
  }
  printf("
");
}
return 0;
}

如果有任何需要澄清的地方，请告诉我.

Let me know if any of this needs clarification.

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