Create a basic matrix in C (input by user !) - c

Question

I'm trying to ask the user to enter the number of columns and rows they want in a matrix, and then enter the values in the matrix... I'm going to let them insert numbers one row at a time.
How can I create such function ?
#include<stdio.h>
main(){
int mat[10][10],i,j;
for(i=0;i<2;i++)
for(j=0;j<2;j++){
scanf("%d",&mat[i][j]);
}
for(i=0;i<2;i++)
for(j=0;j<2;j++)
printf("%d",mat[i][j]);
}
This works for entering the numbers, but it displays them all in one line... The issue here is that I don't know how many columns or rows the user wants, so I cant print out %d %d %d in a matrix form...
Any thoughts?
Thanks :)

Answer 1

How about the following?
First ask the user for the number of rows and columns, store that in say, nrows and ncols (i.e. scanf("%d", &nrows);) and then allocate memory for a 2D array of size nrows x ncols. Thus you can have a matrix of a size specified by the user, and not fixed at some dimension you've hardcoded!
Then store the elements with for(i = 0;i < nrows; ++i) ... and display the elements in the same way except you throw in newlines after every row, i.e.
for(i = 0; i < nrows; ++i)
{
for(j = 0; j < ncols ; ++j)
{
printf("%d\t",mat[i][j]);
}
printf("\n");
}

Answer 2

You need to dynamically allocate your matrix. For instance:
int* mat;
int dimx,dimy;
scanf("%d", &dimx);
scanf("%d", &dimy);
mat = malloc(dimx * dimy * sizeof(int));
This creates a linear array which can hold the matrix. At this point you can decide whether you want to access it column or row first. I would suggest making a quick macro which calculates the correct offset in the matrix.

Answer 3

need a
for(i=0;i<2;i++)
{
for(j=0;j<2;j++)
{
printf("%d",mat[i][j]);
}
printf("\n");
}

Answer 4

#include<stdio.h>
int main(void)
{
int mat[10][10],i,j;
printf("Enter your matrix\n");
for(i=0;i<2;i++)
for(j=0;j<2;j++)
{
scanf("%d",&mat[i][j]);
}
printf("\nHere is your matrix:\n");
for(i=0;i<2;i++)
{
for(j=0;j<2;j++)
{
printf("%d ",mat[i][j]);
}
printf("\n");
}
}

Answer 5

This is my answer
#include<stdio.h>
int main()
{int mat[100][100];
int row,column,i,j;
printf("enter how many row and colmn you want:\n \n");
scanf("%d",&row);
scanf("%d",&column);
printf("enter the matrix:");
for(i=0;i<row;i++){
for(j=0;j<column;j++){
scanf("%d",&mat[i][j]);
}
printf("\n");
}
for(i=0;i<row;i++){
for(j=0;j<column;j++){
printf("%d \t",mat[i][j]);}
printf("\n");}
}
I just choose an approximate value for the row and column. My selected row or column will not cross the value.and then I scan the matrix element then make it in matrix size.

Answer 6

int rows, cols , i, j;
printf("Enter number of rows and cols for the matrix: \n");
scanf("%d %d",&rows, &cols);
int mat[rows][cols];
printf("enter the matrix:");
for(i = 0; i < rows ; i++)
for(j = 0; j < cols; j++)
scanf("%d", &mat[i][j]);
printf("\nThe Matrix is:\n");
for(i = 0; i < rows ; i++)
{
for(j = 0; j < cols; j++)
{
printf("%d",mat[i][j]);
printf("\t");
}
printf("\n");
}
}

Answer 7

//R stands for ROW and C stands for COLUMN:
//i stands for ROW and j stands for COLUMN:
#include<stdio.h>
int main(){
int M[100][100];
int R,C,i,j;
printf("Please enter how many rows you want:\n");
scanf("%d",& R);
printf("Please enter how column you want:\n");
scanf("%d",& C);
printf("Please enter your matrix:\n");
for(i = 0; i < R; i++){
for(j = 0; j < C; j++){
scanf("%d", &M[i][j]);
}
printf("\n");
}
for(i = 0; i < R; i++){
for(j = 0; j < C; j++){
printf("%d\t", M[i][j]);
}
printf("\n");
}
getch();
return 0;
}