can you tell me the wrong

Question

int main() {
int x,n,d,c,swap,array[d],swap
scanf("%d", &x);
switch (x) {
case 1: mergeSort(...);
for (c = 0 ; c < ( n - 1 ); c++)
{
for (d = 0 ; d < n - c - 1; d++)
{
if (array[d] > array[d+1]) /* For decreasing order use < */
{
swap = array[d];
array[d] = array[d+1];
array[d+1] = swap;
}
}
}

break;
case 2: bubbleSort(...);
for (c = 0 ; c < ( n - 1 ); c++)
{
for (d = 0 ; d < n - c - 1; d++)
{
if (array[d] > array[d+1]) /* For decreasing order use < */
{
swap = array[d];
array[d] = array[d+1];
array[d+1] = swap;
}
}
}
break;
default: printf("Invalid choice\n");
}
return 0;
}

Answer 1

Hi,

 

This program is trying to sort the array of numbers. The array cannot be defined before one decides how many member you need, unless it is declared dynamically. 

I have added the include statements to be able to execute scanf and other utilities. Added print statements to see the results. I have added a random number generator to create data, which then can be sorted.  I don't know how merge sort supposed to work, and I have used a book to rewrite bubble sort. (There has been many years since I have written sort code) See code below. This code executes using my compiler. It is limited to 50 number array. I also added a forever while to keep the window open, otherwise one cannot see the output on the PC.

 

I hope this helps -- If you have additional questions. please do not hesitate to contact me. 

 

George

 

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


int main() {
int x,n,d,dd,c,swap,array[50], flag;
srand(time(NULL));
printf("enter member count : ");
scanf("%d",&d);
printf("entered: %d\n",d);
printf("enter option: ");
scanf("%d", &x);
printf("entered: %d\n",x);

n=d;
if(d > 49) {
printf(" too large member count: %d\n",d);
while(true);
exit(1);
}

for(dd=0; dd< d; dd++) {

array[dd] = rand();
printf("random number: %d\n",array[dd]);
}
switch (x) {
case 1: // mergeSort(...);
dd=0;
flag=0;
while(1)
if( array[dd] > array[dd+1] ) {
flag=1;


for (c = 0 ; c < ( n - 1 ); c++)
{

if (array[c] > array[c+1]) /* For decreasing order use < */
{
swap = array[c];
array[c] = array[c+1];
array[c+1] = swap;
}
}

if( ++dd > (n-1))
{
if(flag)
break;
dd-0;
}
dd=0;
flag=0;
} else {
printf("continue\n");
printf(" dd: %d\n",dd);
if(++dd > (n-1)) {
dd=0;
if(flag--)
continue;


for (int k=0; k< d;k++)
printf("member: %d value: %d\n",k,array[k]);
break;
} else {

continue;
}

}

case 2: // bubbleSort(...);
printf("n: %d",n);
for (c = n-1 ; c > 0; c--)
{
for (d = 0 ; d < c; ++d)
{
printf(" d: %d d+1: %d\n",array[d],array[d+1]);
if (array[d] > array[d+1])/* For decreasing order use < */
{
swap = array[d];
array[d] = array[d+1];
array[d+1] = swap;
}
}
}
break;
default: printf("Invalid choice\n");
break;
for (int k=0; k< d;k++)
printf("member: %d value: %d\n",k,array[k]);
}
while(true);
return 0;
}