该计划的作用： 从文件中读取带有nrRows行和nrColomns colomns的矩阵（2d数组）。 矩阵的所有元素都是[0,100]之间的int数。 程序必须重新排列矩阵内的所有元素，使每个元素等于它所在行的索引。
离。 5将在第58行的第5行，第58行。
结果写在一个文件中。 我只需要使用1个矩阵，所有内存都是动态分配的。 如果我必须添加或擦除元素，我也会重新调整矩阵的内存。 另外，我需要保持矩阵的形状。
离。 3排2个colomns。不是3行，其中第1行有1个colomn，第2行有3个colomns等。
我认为重新分配在我的c程序中不起作用。该程序本身工作正常。 帮助
#include<stdio.h>
#include<malloc.h>
unsigned short maxim(unsigned short A[100])
{
unsigned short max = 0;
for (unsigned short i = 0; i<100; ++i)
if (A[i] > max)
max = A[i];
return max;
}
void main()
{
FILE *pFile = fopen("test.txt", "r");
unsigned short nrRows, nrColomns;
/* If empty exit */
if (pFile == NULL)
return;
fscanf(pFile, "%d", &nrRows);
fscanf(pFile, "%d", &nrColomns);
/* Memory Allocation */
int** V = (int**)malloc(nrRows * sizeof(int*)); /* Number of lines */
for (unsigned short i = 0; i < nrRows; ++i)
V[i] = (int*)malloc(nrColomns * sizeof(int)); /* Number of colomns */
/* Read the elements */
for (unsigned short i = 0; i < nrRows; ++i)
for (unsigned short j = 0; j < nrColomns; ++j)
fscanf(pFile, "%d", &V[i][j]);
/* Find max + array */
unsigned short A[100] = { '\0' }; unsigned short max = 0;
for (unsigned short i = 0; i < nrRows; ++i)
for (unsigned short j = 0; j < nrColomns; ++j)
{
/* How many times each value between [0 and 100) is found inside the matrix */
A[V[i][j]]++;
/* Find the biggest element */
if (V[i][j] > max)
max = V[i][j];
}
/* Memory Reallocation */
unsigned short maxA = maxim(A); unsigned short ok = 0;
if (maxA > nrColomns){
nrColomns = maxA;
ok++;
}
if (max + 1 > nrRows){
nrRows = max + 1;
ok++;
}
//if (ok != 0)
//{
*V = realloc(*V, nrRows * sizeof(int*));
for (unsigned short i = 0; i < nrRows; i++)
V[i] = (int*)realloc(V, nrColomns * sizeof(int));
//}
/* Rearrange Values */
unsigned short bool = 1;
while (bool != 0)
{
bool = 0;
for (unsigned short i = 0; i < nrRows; ++i)
{
for (unsigned short j = 0; j < nrColomns; ++j)
{
if (V[i][j] != i)
{
/* Swap elements */
unsigned short k = 0;
while (k < nrColomns)
{
if (V[V[i][j]][k] != V[i][j])
{
bool = 1;
/* Do the swapping */
int swap = V[V[i][j]][k];
V[V[i][j]][k] = V[i][j];
V[i][j] = swap;
break;
}
else k++;
}
}
}
}
}
/* Extra Reallocation */
if (maxA < nrColomns)
{
nrColomns = maxA;
for (unsigned short i = 0; i < nrRows; ++i)
V[i] = (int*)realloc(V, nrColomns * sizeof(int));
}
/* Print Result into file */
pFile = fopen("out.txt", "w");
fprintf(pFile, "%d %d \n", nrRows, nrColomns);
for (unsigned short i = 0; i < nrRows; ++i)
{
for (unsigned short j = 0; j < nrColomns; ++j)
fprintf(pFile, "%d ", V[i][j]);
fprintf(pFile, "\n");
}
fclose(pFile);
_getch();
/* Memory Deallocation */
for (unsigned short i = 0; i < nrRows; ++i)
free(V[i]);
free(V);
}
这很奇怪......我在这个问题上已经失去了足够的时间。
test.txt的例子
4 3 1 2 2 0 0 0 1 1 3 5 3 2
答案 0 :(得分：0)
我总是讨厌realloc。如果你可以避免它，请按照我的建议：
有关您的代码的一些要点，无论问题如何：
for块内声明变量。但是它在所有版本的C中都不起作用。取决于编译器。unsigned short。经典整数可以。代码：
#include <stdio.h>
#include <stdlib.h>
int min(int a, int b) {
return (a < b) ? a : b;
}
void updateDimensions(int*** currentArray, unsigned short currentRowsNb, unsgined short currentColumnsNb, unsigned short newRowsNb, unsigned short newColumnsNb) {
int i;
int j;
int error;
int** res;
if(*currentArray != NULL && (newRowsNb != currentRowsNb || newColumnsNb != currentColumnsNb)) {
error = 0;
/* Memory allocation */
res = (int**)malloc(newRowsNb* sizeof(int*));
if(res != NULL) {
for(i=0 ; i < newRowsNb; i++) {
res[i] = (int*)malloc(newColumnsNb* sizeof(int));
if(res[i] == NULL) {
error = 1;
fprintf(stderr, "allocation error"); // Optional
while(--i >= 0)
free(res[i]);
free(res);
}
}
} else {
fprintf(stderr, "Allocation error);
error = 1;
}
/* End of memory allocation */
if(!error) {
/* Copy of the array */
for(i=0 ; i < min(currentRowsNb, newRowsNb) ; i++)
for(j=0 ; j < min(currentColumnsNb, newColumnsNb) ; j++)
res[i][j] = (*currentArray)[i][j];
/* End of copy */
/* Free current array */
for(i=0 ; i < currentNrRows ; i++)
free((*currentArray)[i]);
free(*currentArray);
/* End of free */
*currentArray = res; // Assign new array to current one.
}
}
}
unsigned short maxim(unsigned short A[100]) {
unsigned short max = 0;
unsigned short i;
for(i = 0 ; i < 100 ; i++)
if(A[i] > max)
max = A[i];
return max;
}
void main() {
/* Variable declaration */
unsigned short i;
unsigned short j;
unsigned short k;
unsigned short ok;
unsigned short max;
unsigned short maxA;
unsigned short nrRows;
unsigned short my_bool;
unsigned short nrColomns;
unsigned short A[100];
int swap;
int newNrRows;
int newNrColumns;
int tempInt;
int **V;
FILE *pFile;
/* Variable initialization */
pFile = fopen("test.txt", "r");
if(pFile == NULL)
return;
fscanf(pFile, "%d", &nrRows);
fscanf(pFile, "%d", &nrColomns);
max = 0;
my_bool = 1;
for(i=0 ; i < 100 ; i++)
A[i] = '\0';
/* Memory Allocation */
V = (int**)malloc(nrRows * sizeof(int*)); /* Number of lines */
if(V == NULL) {
fprintf(stderr, "Allocation error"); // Writes in the error output (optional)
return;
}
for (i = 0; i < nrRows; ++i)
V[i] = (int*)malloc(nrColomns * sizeof(int)); /* Number of colomns */
/* If allocation error */
if(v[i] == NULL) {
fprintf(stderr, "Allocation error"); // Optional
/* The following is mandatory */
while(--i > 0) { // Free all cell already allocated
free(A[i]);
}
free(A);
return;
}
}
/* End of memory allocation */
/* Read the elements */
for (i = 0; i < nrRows; ++i)
for (j = 0; j < nrColomns; ++j)
fscanf(pFile, "%d", &V[i][j]); // That assume you only have digit (0 to 9) in your file.
/* If you have a delimiter between numbers (here i'll take ';' as example, use this */
fscanf(pFile, "%[^;]%*d", &v[i][j]);
/* If you have many delimiters (here ';', ' ' and '\n' as example) */
fscanf(pFile, "%[^;\n ]%*d", &v[i][j]);
/* End of reading
/* Find max + array */
for (i = 0; i < nrRows; ++i)
for (j = 0; j < nrColumns; ++j) {
/* How many times each value between [0 and 100) is found inside the matrix */
A[V[i][j]]++;
/* Find the biggest element */
if (V[i][j] > max)
max = V[i][j];
}
/* Memory Reallocation */
maxA = maxim(A);
if (maxA > nrColomns) {
newNrColumns = maxA;
ok++;
}
if (max + 1 > nrRows) {
newNrColumns = max + 1;
ok++;
}
if (ok != 0) {
updateDimensions(&V, nrRows, nrColumns, newNrRows, newNrColumns);
nrRows = newNrRows;
nrColumns = newNrColumns;
}
/* Rearrange Values */
while (my_bool != 0) {
my_bool = 0;
for (i = 0; i < nrRows; ++i) {
for (j = 0; j < nrColomns; ++j) {
if (V[i][j] != i) {
/* Swap elements */
k = 0;
while (k < nrColomns) {
if (V[V[i][j]][k] != V[i][j]) {
my_bool = 1;
/* Do the swapping */
swap = V[V[i][j]][k];
V[V[i][j]][k] = V[i][j];
V[i][j] = swap;
break;
} else {
k++;
}
}
}
}
}
}
/* Extra Reallocation */
if (maxA < nrColomns) {
newNrColumns = maxA;
updateDimension(&V, nrRows, nrColumns, newNrRows, newNrColumns);
}
/* Print Result into file */
fclose(pFile);
pFile = fopen("out.txt", "w");
if(pFile == NULL) {
fprintf(stderr, "Error while openning file");
} else {
fprintf(pFile, "%d %d \n", nrRows, nrColomns);
for (unsigned short i = 0; i < nrRows; ++i) {
for (unsigned short j = 0; j < nrColomns; ++j)
fprintf(pFile, "%d ", V[i][j]);
fprintf(pFile, "\n");
}
fclose(pFile);
}
_getch();
/* Memory Deallocation */
for (i = 0; i < nrRows; ++i)
free(V[i]);
free(V);
}
注意：我没有尝试编译它，它可能有错误（特别是在(*currentArray)[i][j]之类的东西上）。对不起英语不好^^＆＃39;