Question

Simple C programming issuse Please help urgent!

Answer 1

#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <string.h>


void sum_row1(int matrix[30][30], int *sum1);
void sum_diagonal(int matrix[][30], double *sumd, double *y);

int main(void)

{ int matrix[30][30], matrix_null[30][30];
int i, j, k=0, sum1, count_num_zero=0, count=0;
double sumd, avg_sumd;

srand(time(NULL));


for(k=0;k<3;k++)
{

for(i=0;i<30;i++)
{for(j=0; j<30 ;j++)
{matrix[i][j]= (rand()%10);}
}

sum_diagonal(matrix, &sumd, &avg_sumd);

printf("%lf\n", avg_sumd);

if (avg_sumd<7)
{for(i=0; i<30;i++)
{for(j=0; j<30;j++)
matrix[i][j]= 0;
}
}

else
{

for(i=0; i<30;i++)
{for(j=0; j<30;j++)
matrix[i][j]= matrix[i][j];
}

for(i=0;i<30;i++)
{for(j=0; j<30 ;j++)
printf("%d ", matrix[i][j]);
printf("\n");
}
}

avg_sumd=0;
}

return(0);
}

void sum_diagonal(int matrix[][30], double *sumd, double *y)

{ int i, j;

*y=0;
for(i=0;i<30;i++)
for(j=i ;j!=i+1; j++)
{*sumd+=matrix[i][j];
}
*y= *sumd/30;
}

Answer 2

I want a program to keep generating that matrix, and keep calculating a new average for its diagonal, but this code keeps writing over the old average of the diagonal...
could someone help me fix this bug, its driving me crazyyyyyyyyyyyyyyyyyyyyyy

Answer 3

@Mertsj @hartnn

Answer 4

@ParthKohli

Answer 5

@rajathsbhat @timo86m @thomaster @Callisto

Answer 6

Mercy, I don't know C.

Answer 7

:( ok thanks

Answer 8

do you know anyone that knows C?

Answer 9

I'm not sure

Answer 10

you need to create a new array?

Answer 11

In your function, sum_diagonal, you don't need the 2nd for loop.
for(i=0;i<30;i++)
for(j=i ;j!=i+1; j++)
{
*sumd+=matrix[i][j];
}

This code will produce the diagonal:
for(i=0;i<30;i++)
*sumd+=matrix[i][i];



The specific problem you're having, though, is that you're storing avg_sumd in the same variable. Instead, replace avg_sumd with avg_sumd[k] - the declaration should be avg_sumd[3].