C语言 从文本文件中读取并存储在二维数组中
声明：本页面是StackOverFlow热门问题的中英对照翻译，遵循CC BY-SA 4.0协议，如果您需要使用它，必须同样遵循CC BY-SA许可，注明原文地址和作者信息，同时你必须将它归于原作者（不是我）：StackOverFlow
原文地址: http://stackoverflow.com/questions/18942719/
Warning: these are provided under cc-by-sa 4.0 license. You are free to use/share it, But you must attribute it to the original authors (not me):
StackOverFlow
Reading from a text file and storing in a 2D array
提问by Butterflay
I've been trying to store a matrix input in a txt file in a array but it show me this: this is the code
我一直在尝试将矩阵输入存储在一个数组中的 txt 文件中，但它向我展示了这一点：这是代码
#include <stdio.h>
int main()
{
int c, i, j, row, col, nl, cr;
row = col = nl = cr = 0;
FILE *fp = fopen("g.txt", "r");
// Figure out how many rows and columns the text file has
while ((c = getc(fp)) != EOF)
{
if (c == '\n')
nl++;
if (c == '\r')
cr++;
col++;
if (c == '\n')
row++;
putchar(c);
}
col = (col - (nl + cr));
col = (int) (col/row);
// printf("\nnumber of rows is %d\n", row);
// read letters into array
char array[row][col];
if ( fp )
{
for ( ;; )
{
c = getc(fp);
if ( c == EOF )
{
break;
}
if ( c != '\n' && c != '\r' )
{
array[i][j] = c;
if ( ++j >= col )
{
j = 0;
if ( ++i >= row )
{
break;
}
}
}
}
fclose(fp);
}
for ( i = 0; i < row; i++ )
{
for ( j = 0; j < col; j++ )
{
putchar( array[i][j]);
}
putchar('\n');
}
return 0;
}
somone have any idea please? exemple of the txt file :
有人知道吗？txt 文件示例：
255 50 9 50 1 50 50 1
50 255 50 50 50 50 50 50
50 50 255 50 50 50 50 50
8 50 50 255 50 50 50 50
50 50 50 50 255 50 50 50
50 50 50 50 50 255 50 50
1 50 50 50 50 50 255 50
2 50 50 50 50 50 50 255
my program show me this:
我的程序向我展示了这个：
255 50 9 50 1 50 50 1
50 255 50 50 50 50 50 50
50 50 255 50 50 50 50 50
8 50 50 255 50 50 50 50
50 50 50 50 255 50 50 50
50 50 50 50 50 255 50 50
1 50 50 50 50 50 255 50
2 50 50 50 50 50 50 255 $■( 1gíuát09■????¤?u"òávD ê$[
? e2( ? l ? ■???
ê$[ ? l -2( O??v[ 4■( Q?á
v? #?áv┬2║O?|?v ?|?ve┬ív
■( x■( ?|?v ó2?????@■( á?v╚♀[ L
■( wˉ?v? ê■( I┴áv?|?v↓┴áv~2║O
ó2?????\■( ■???─?( e┬íví┬29??
for the input file it show the good one ,but the problem is for the array output i don't undrestand why it show me this caracters
对于输入文件，它显示了良好的文件，但问题在于数组输出，我不明白为什么它会向我显示这个字符
回答by Filipe Gon?alves
You never change j, it always remains 0, so you're writing every position a[i][0]. atoi(line); will convert the first number in the line only. That's why your program is only storing the first column.
你永远不会改变 j，它总是保持为 0，所以你正在写每个位置 a[i][0]。atoi（线）；将只转换行中的第一个数字。这就是为什么你的程序只存储第一列。
A possible approach to fix this would be something like:
解决此问题的可能方法是：
#include <stdio.h>
#include <stdlib.h>
int main(void) {
int i=0,totalNums,totalNum,j=0;
size_t count;
int numbers[100][100];
char *line = malloc(100);
FILE *file; /* declare a FILE pointer */
file = fopen("g.txt", "r"); /* open a text file for reading */
while(getline(&line, &count, file)!=-1) {
for (; count > 0; count--, j++)
sscanf(line, "%d", &numbers[i][j]);
i++;
}
totalNums = i;
totalNum = j;
for (i=0 ; i<totalNums ; i++) {
for (j=0 ; j<totalNum ; j++) {
printf("\n%d", numbers[i][j]);
}
}
fclose(file);
return 0;
}
That code will read the entire line, and then parse it number by number until no more numbers are there.
该代码将读取整行，然后逐个解析它，直到没有更多数字为止。
I didn't really understand if input is supposed to be integers or doubles, note that you declare a 2D array of doubles but then you call atoi(). The code I posted assumes it's integers, but then make sure to change your array to a 2D array of ints (or if they really are doubles, change the format string in sscanf).
我真的不明白输入应该是整数还是双精度数，请注意，您声明了一个双精度数的二维数组，然后调用了 atoi()。我发布的代码假定它是整数，但请确保将数组更改为整数的二维数组（或者如果它们确实是双精度数，请更改 sscanf 中的格式字符串）。
回答by user1502952
#include <iostream>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
using namespace std;
int main(void)
{
FILE * fp;
char * line = NULL;
size_t len = 0;
ssize_t read;
const char *s = " ";
char *token = NULL;
int i = 0;
double arr[200];
int j;
fp = fopen("g.txt", "r");
if (fp == NULL)
{
printf("Error opening");
exit(EXIT_FAILURE);
}
while ((read=getline(&line, &len, fp)) != -1)
{
token = strtok(line, s);
while(token != NULL)
{
arr[i] = atoi(token);
printf("%f\n", arr[i]);
token=strtok(NULL,s);
i++;
}
}
exit(EXIT_SUCCESS);
return 0;
}
getlinewill read file line by line and strtokwill split entries based on space and will store seperately entries in array. Also single dimensional array is enough to store values.
getline将逐行读取文件，并strtok根据空间拆分条目，并将条目单独存储在数组中。一维数组也足以存储值。
