C使用動態分配從文件讀取行和空格
[英]C reading lines and spaces from a file using dynamic allocation
問題描述
我試圖通過使用逆向工程過程從文件中讀取矩陣。 我嘗試做的第一部分是使用malloc或calloc創建文件。 我使用malloc是因為提示用戶輸入的行數或列數。 我還制作了要在屏幕上打印出的最終矩陣和用戶定義的文件名。
我現在遇到的問題是我能夠在第二部分上獲取文件名，但是一旦找到文件名，程序將凍結並停止執行下一個操作。
這是我的代碼如下：
//preprocessors
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
//macros
#define STRING_MAX 50
//function prototypes
void printDiagonal (double ** m, int r, int c);
int main (int argc, char * argv [ ])
{
FILE * ptrIn;
FILE * ptrOut;
char inFileName [STRING_MAX];
char outFileName [STRING_MAX];
int row;
int col;
int r;
int c_temp;
int c;
char spaces;
char lines;
int i, j, k;
int ctrSpaces = 0;
int ctrLines = 0;
int ctrH = 0;
int ctrV = 0;
double matrixVals;
double ** matrixIn;
double ** matrixOut;
//get a file name first
printf ("\nEnter a file name >> ");
scanf ("%s", inFileName);
//open the file
ptrIn = fopen (inFileName, "w");
//get matrix dimensions
printf ("\nEnter the row and column sizes >> ");
scanf ("%d", &row);
scanf ("%d", &col);
printf ("\nRows >> %d\nCols >> %d\n\n", row, col);
matrixIn = (double **) malloc (row * sizeof (double *));
if (matrixIn == NULL)
{
printf ("\nSORRY, NOT ENOUGH MEMORY!\n\n");
exit (0);
}
for (i = 0; i < row; i ++ )
{
matrixIn [i] = (double *) malloc (col * sizeof (double));
if (matrixIn [i] == NULL)
{
printf ("\nSORRY, NOT ENOUGH MEMORY!\n\n");
exit (0);
}
}
//input the values into the matrix
printf ("\nEnter the values into the matrix >> \n\n");
for (i = 0; i < row; i ++)
{
for (j = 0; j < col; j ++)
{
printf ("\n\nEnter [%d][%d] of [%d][%d] >> ", (i + 1), (j + 1), row, col);
scanf ("%lf", &matrixIn [i] [j]);
}
}
//print out the matrix
printf ("\nElements in the matrix >> \n\n");
for (i = 0; i < row; i ++)
{
for (j = 0; j < col; j ++)
{
printf ("%.3lf\t", matrixIn [i][j]);
fprintf (ptrIn, "%.3lf\t", matrixIn [i][j]);
}
printf ("\n");
fprintf (ptrIn, "\n");
}
printf ("\n");
fprintf (ptrIn, "\n");
for (i = 0; i < row; i ++)
{
free (matrixIn [i]);
}
free (matrixIn);
fclose (ptrIn);
printf ("\n-----------------------------------------------------------------------------------------------------------------\n\n");
/**------------------------------------------------------------------------------------------------------------------------------------------------------------------------------**/
//now retrieve the file by first getting user input for file name and check that the file exists
FILE_NAME:
printf ("\nEnter the name of file to access >> ");
scanf ("%s", outFileName);
printf ("\nThe name of the file is >> %s\n\n", outFileName);
//now open the file
ptrOut = fopen (outFileName, "r");
//check that the file exists
if (ptrOut == NULL)
{
printf ("\nSORRY, THE FILE DOES NOT EXIST. PLEASE ENTER A VALID FILE NAME.\n\n");
goto FILE_NAME;
}
//get the number of rows and columns
for (lines = fgetc (ptrOut); lines != EOF; lines == fgetc (ptrOut))
{
if (lines == '\t' || lines == ' ')
{
ctrLines ++;
if (lines == EOF)
{
break;
}
}
}
c_temp = ctrLines;
for (spaces = fgetc (ptrOut); spaces != EOF; spaces = fgetc(ptrOut))
{
if (spaces == '\n')
{
ctrSpaces ++;
if (spaces == EOF)
{
break;
}
}
}
r = ctrSpaces;
//total number of rows is:
c = c_temp / r;
printf ("\nNumber of rows >> %d\n\nNumber of columns >> %d\n\n", r, c);
matrixOut = (double **) malloc (r * sizeof (double *));
if (matrixOut == NULL)
{
printf ("\nSorry, not enough memory!\n\n");
exit (0);
}
for (i = 0; i < r; i ++)
{
matrixOut [i] = (double *) malloc (c * sizeof (double));
if (matrixOut [i] == NULL)
{
printf ("\nSorry, not enough memory!\n\n");
exit (0);
}
}
for (i = 0; i < r; i ++)
{
free (matrixOut [i]);
}
free(matrixOut);
fclose (ptrOut);
//reopen the file and get the information from the file
ptrOut = fopen (outFileName, "r");
matrixOut = (double **) malloc (c * sizeof (double *));
for (i = 0; i < r; i++)
{
matrixOut [i] = (double *) malloc (c * sizeof (double));
}
printf ("\nMatrix from File %s of dimensions %d X %d >>\n\n", outFileName, r, c);
for (i = 0; i < r; i ++)
{
for (j = 0; j < c; j ++)
{
fscanf (ptrOut, "%lf", &matrixVals);
matrixOut [i] [j] = matrixVals;
printf ("%.3lf\t", matrixOut [i] [j]);
}
printf ("\n");
}
printf ("\n");
for (i = 0; i < r; i ++)
{
free (matrixOut [i]);
}
free(matrixOut);
fclose (ptrOut);
return (0);
}
這是我的輸出： https : //1drv.ms/u/s ! AqM2tvkVzTumh58mcliiAUKD9Uu7Ew 。
為了澄清我的問題。
謝謝
1 個解決方案
解決方案1
0 已采納 2018-05-10 20:08:05
我終於感謝了user3629249。 我只需要分開讀取行號和讀取行號這兩個操作。 對於行號，我必須從總行數中減去1，因為它在EOL之后增加了\\0 。
這是我的最終代碼（以及我最初沒有提到的用於打印方陣的主要和“次要”對角線的功能）。
//preprocessors
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
//macros
#define STRING_MAX 50
//function prototypes
void printMajorDiagonal (double ** m, int r, int c);
void printMinorDiagonal (double ** m, int r, int c);
int main (int argc, char * argv [ ])
{
FILE * ptrIn;
FILE * ptrOut;
char inFileName [STRING_MAX];
char outFileName [STRING_MAX];
int row;
int col;
int r;
int c_temp;
int c;
char spaces;
char lines;
char ch;
int i, j, k;
int ctrSpaces = 0;
int ctrLines = 0;
int ctrH = 0;
int ctrV = 0;
int charCount = 0;
int lineCount = 0;
double matrixVals;
double ** matrixIn;
double ** matrixOut;
//get a file name first
printf ("\nEnter a file name >> ");
scanf ("%s", inFileName);
//open the file
ptrIn = fopen (inFileName, "w");
//get matrix dimensions
printf ("\nEnter the row and column sizes >> ");
scanf ("%d", &row);
scanf ("%d", &col);
printf ("\nRows >> %d\nCols >> %d\n\n", row, col);
matrixIn = (double **) malloc (row * sizeof (double *));
if (matrixIn == NULL)
{
printf ("\nSORRY, NOT ENOUGH MEMORY!\n\n");
exit (0);
}
for (i = 0; i < row; i ++ )
{
matrixIn [i] = (double *) malloc (col * sizeof (double));
if (matrixIn [i] == NULL)
{
printf ("\nSORRY, NOT ENOUGH MEMORY!\n\n");
exit (0);
}
}
//input the values into the matrix
printf ("\nEnter the values into the matrix >> \n\n");
for (i = 0; i < row; i ++)
{
for (j = 0; j < col; j ++)
{
printf ("\n\nEnter [%d][%d] of [%d][%d] >> ", (i + 1), (j + 1), row, col);
scanf ("%lf", &matrixIn [i] [j]);
}
}
//print out the matrix
printf ("\nElements in the matrix >> \n\n");
for (i = 0; i < row; i ++)
{
for (j = 0; j < col; j ++)
{
printf ("%.3lf\t", matrixIn [i][j]);
fprintf (ptrIn, "%.3lf\t", matrixIn [i][j]);
}
printf ("\n");
fprintf (ptrIn, "\n");
}
printf ("\n");
fprintf (ptrIn, "\n");
for (i = 0; i < row; i ++)
{
free (matrixIn [i]);
}
free (matrixIn);
fclose (ptrIn);
printf ("\n-----------------------------------------------------------------------------------------------------------------\n\n");
/**------------------------------------------------------------------------------------------------------------------------------------------------------------------------------**/
//now retrieve the file by first getting user input for file name and check that the file exists
FILE_CHECK:
printf ("\nEnter the name of file to access >> " );
scanf ("%s", outFileName);
printf ("\nThe name of the file is >> %s\n\n", outFileName);
//now open the file
ptrOut = fopen (outFileName, "r");
if (ptrOut == NULL)
{
printf ("Sorry, the file does not exist. Re-enter another file-name.\n\n");
goto FILE_CHECK;
}
//read lines first - total number of lines == total number of rows
for (lines = getc (ptrOut); lines != EOF; lines = getc (ptrOut))
{
if (lines == '\n')
{
ctrLines ++ ;
}
}
r = ctrLines - 1;
matrixOut = (double **) malloc (r * sizeof (double *));
if (matrixOut == NULL)
{
printf ("\nSorry, not enough memory!\n\n");
exit (0);
}
free (matrixOut);
printf ("\nRows >> %d\n\n", r);
/*******************************************************************************************************************************************/
//open the file again to count columns
ptrOut = fopen (outFileName, "r");
for (spaces = getc (ptrOut); spaces != EOF; spaces = getc (ptrOut))
{
if (spaces == ' ' || spaces == '\t' || spaces == '\b')
{
ctrSpaces ++ ;
}
}
c_temp = ctrSpaces;
c = c_temp / r;
printf ("\nCols >> %d\n\n", c);
for (i = 0; i < r; i ++)
{
matrixOut [i] = (double *) malloc (c * sizeof (double));
if (matrixOut [i] == NULL)
{
printf ("\nSorry, not enough memory!\n\n");
exit (0);
}
}
for (i = 0; i < r; i ++ )
{
free (matrixOut [i]);
}
fclose (ptrOut);
//reopen the file again to read the matrix elements line by line
ptrOut = fopen (outFileName, "r");
matrixOut = (double **) malloc (r * sizeof (double *));
for (i = 0; i < r; i ++)
{
matrixOut [i] = (double *) malloc (c * sizeof (double));
}
//print out the matrix here
printf ("\nThe matrix in the file %s of size %d x %d.\n\n", outFileName, r, c);
for (i = 0; i < r; i ++)
{
for (j = 0; j < c; j++)
{
fscanf (ptrOut, "%lf", &matrixVals);
matrixOut [i] [j] = matrixVals;
printf ("%.3lf\t", matrixOut [i] [j]);
}
printf ("\n");
}
printf ("\n");
printMajorDiagonal (matrixOut, r, c);
printMinorDiagonal (matrixOut, r, c);
for (i = 0; i < r; i ++)
{
free (matrixOut [i]);
}
free (matrixOut);
fclose (ptrOut);
return (0);
}
//function definitions
void printMajorDiagonal (double ** m, int r, int c)
{
//prints out the major diagonal
int i, j;
if (r == c)
{
printf ("\nMajor Diagonal >> \n\n");
for (i = 0; i < r; i ++)
{
printf ("%.3lf\t", m [i] [i]);
}
printf ("\n");
}
else if (r != c)
{
printf ("\nThe major diagonal cannot be printed since the given matrix is not a square matrix.\n\n");
}
}
void printMinorDiagonal (double ** m, int r, int c)
{
//prints out the opposite "minor" diagonal
int i, j;
if (r == c)
{
printf ("\nMinor Diagonal >> \n\n");
for (i = 0; i < r; i ++)
{
printf ("%.3lf\t", m [r - i - 1] [i]);
}
printf ("\n");
}
else if (r != c)
{
printf ("\nThe major diagonal cannot be printed since the given matrix is not a square matrix.\n\n");
}
}
再次感謝所有參與幫助我的人。 我的錯誤是在第一次進行行計數迭代后無法重新啟動文件。
非常感謝StackOverFlow!
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