Thread: sorting the matrix question..

I'll put my comments in the code.

Code:

#include <stdio.h>

int main(){//star
	int i,j,k,temp;
	int rows,cols,jndex,input;
	int sum2=0;
	printf("enter rows and cols [1..50] ==> ");  //move these 2 line down below 
	scanf("%d %d",&rows,&cols);                      //printf(" enter power"); 
	int matrix[rows][cols];
	int sum[rows][cols];
	int temp1[rows][cols];   //changed name of array to temp1 - temp is used by an int
	int transpose [cols][rows];
	int index,kndex,tndex,gndex,lndex;
        int rows_sum[rows];                           
	printf("enter power:");
	scanf("%d",&input);

//Do you want to do a sort via the index that I wrote about, or do you want to use the 
//the first sort I showed you?

//I wouldn't do both.

	for (index = 0;  index < rows; index++)
	{
	    rows_sum[index]=0;
		for (kndex = 0; kndex < cols; kndex++)
		{
			matrix[index][kndex] = 0;
			sum[index][kndex] = 0;
			temp1[index][kndex] = 0;
			transpose[index][kndex] = 0;
		}//end inner for
	}//end outer for
	printf("enter numbers in a row for a matrix:"); //stat input
	for (index = rows - 1;index >= 0; index--)
	{
		for (kndex = cols - 1; kndex >= 0; kndex--)
		{
			scanf("%d", &matrix[index][kndex]);
			transpose[kndex][index] = matrix[index][kndex];
		}
	}
	getchar();  //needed because of scanf()
	//end input
	//start power operation
	//  rows sum
	for (index = 0; index < rows; index++)
	{
		for (kndex = 0; kndex < cols; kndex++)
			rows_sum[index]=rows_sum[index]+matrix[index][kndex];
		printf("\n");
	}
      //  end rows sum

	 

for(i = 0; i <rows - 1; i++)  {       
   for(j = i + 1; j <rows; j++)  {   
      if(rows_sum[i] >rows_sum[j])   {
         temp = rows_sum[i];
         rows_sum[i] = rows_sum[j];
         rows_sum[j] = temp;
 
         //now swap the rows elements, from row j to row i
         for(k = 0; k <rows; k++)   {
            temp = matrix[i][k];                                      //here is line 62
            matrix[i][k] = matrix[j][k];
            matrix[j][k] = temp;
         }
      }
   }
}//end main

That's all I see wrong, right now (it's very late, here). Let me know what kind of sort you want - and consider getting rid of index, kndex, gndex, etc. It's confusing. Standard practice is to use i or j, as you counters inside for loops, and here, row, or r, and col, or c, would be a natural to use. I highly recommend it.

So far, I can't get your program to compile, but I'll work with it for a bit longer.

This is as far as I could get with your full program. Note the corrections in the code.

Code:

#include <stdio.h>

int main()   { //star
	int i,j,k,temp;
	int rows = 4;
   int cols = 4;
   int jndex,input;
//	int sum2=0;  sum2 is never used

   /* You can't make an array without telling it's size. rows and cols
   have not been assigned a value, yet. 
   */
   int matrix[4][4];
//	int matrix[rows][cols];
//	int sum[rows][cols];
   int sum[4][4];
//	int temp1[rows][cols];
   int temp1[4][4];
//	int transpose [cols][rows];
   int transpose [4][4];
	int index,kndex,tndex,gndex,lndex;
   int rows_sum[4];
   //int rows_sum[rows]; //rows could be ANY value, still.

/* your program isn't designed for this
   printf("enter rows and cols [1..50] ==> ");
	scanf("%d %d",&rows,&cols);
*/
	printf("enter power:");
	scanf("%d",&input);

/* You can save yourself this code, just by making the array initialize to
zero's, when you declare it:

row_sum[4] = { 0 };

This only works when you first declare them, not at any later time
*/
	for (index = 0; index < rows; index++)
	{
	    rows_sum[index]=0;
		for (kndex = 0; kndex < cols; kndex++)
		{
			matrix[index][kndex] = 0;
			sum[index][kndex] = 0;
			temp1[index][kndex] = 0;
			transpose[index][kndex] = 0;
		}//end inner for
	}//end outer for
	printf("enter numbers in a row for a matrix:"); //stat input
	for (index = rows - 1;index >= 0; index--)
	{
		for (kndex = cols - 1; kndex >= 0; kndex--)
		{
			scanf("%d", &matrix[index][kndex]);
			transpose[kndex][index] = matrix[index][kndex];
		}
	}
	i = getchar();  //needed because of scanf()
	//end input
	//start power operation
	//  rows sum
	for (index = 0; index < rows; index++)
	{
		for (kndex = 0; kndex < cols; kndex++)
			rows_sum[index]=rows_sum[index]+matrix[index][kndex];
		printf("\n");
	}
      //  end rows sum

for(i = 0; i <rows - 1; i++)  {       
   for(j = i + 1; j <rows; j++)  {   
      if(rows_sum[i] >rows_sum[j])   {
         temp = rows_sum[i];
         rows_sum[i] = rows_sum[j];
         rows_sum[j] = temp;
      }  //you missed this brace :)
         //now swap the rows elements, from row j to row i
         for(k = 0; k <rows; k++)   {
            temp = matrix[i][k];                                      //here is line 62
            matrix[i][k] = matrix[j][k];
            matrix[j][k] = temp;
         }
      }
   }

   //print the swapped matrix
   for(i = 0; i < rows; i++)  {
      putchar('\n');
      for(j = 0; j < cols; j++)  
         printf(" %d", matrix[i][j]);
   }

   i = getchar();
   return 0;

}//end main

It compiles, but I'm not sure how far it will run, or whether it's accurate. You need to get some more print statements in there, to see if your program is working right.

good luck!