multidimension array

[nera]

Hey guys,
This is actually a easy problem; I'm just having problems because i just started using it and knowing the concept of arrays. Anyways the program wants to defines a two dimensional array of size [4][4] initialized to zero; for the first row add 5 to each element and for the third row add 2 and multiple by 3, then for the second column add 2 to each element, print out the array, then find the sum of one of the diagonalize.

This what i have so far:

#include<stdio.h>

int main () {

int my[4][4];
int i,j;

for(i = 0; i < 4; i++)
my[0][i] = 5;

for(i = 0; i < 4; i++) 
my [2][i] = 2;
my[2][i] = my[2][i] * 3;


for(i = 0; i < 4; i++){
for(j = 0; j < 4; j++)
printf("%d", my[i][j]);
printf("\n");
}
printf("\n\n");

return 0;
}

Any help would be appreciated, thanks.

[anduril462]

You're off to a good start. Proper indentation would highlight at least one problem. Your second for loop needs a set of curly braces around the two statements. Some more problems:

• You never initialize my to all zeros, so some of the elements have garbage in them
• Technically, you aren't adding 5 or 2 to the elements. Try my[0][i] += 5;, my[2][i] +=2; and my[2][i] *= 3;
• You don't add 2 to the elements of the second column.
• You never calculate the sum of a diagonal. The elements of the main diagonal are where the row and column have the same index.
• You should print your matrix with some space between the numbers, so it's easier to read. Try "%4d" instead of "%d" on line 18.

[nera]

Yea that helped me get the result; Thanks alot!