[tawandapro]

In this one there is a scenario whereby 20 children are in a room. every fourth one is deleted until. there are none left. Im getting 1 1 1 1 1 1 1 1 as the output. I can't figure out what is wrong with my code at the moment. Help would be greatly appreciated

#include<stdio.h>
#include<stdlib.h>
int main()
{
int i, n;
struct mode
{
int num;
struct mode * next;
};
struct mode *header, *last, *temp, *present;
header = NULL;
printf("Enter the amount of people \n");
scanf("%d", &n);
for (i=1; i<n; i++)
{
temp = malloc(sizeof(struct mode));
temp -> num = 1;
temp -> next = NULL;
if (i == 1)
header = temp;
else
last-> next = temp;
last = temp;
}
present = header;
while (present != NULL)
{
printf("%6d", present->num);
temp = present;
present = present ->next;
free(temp);
}
return 0;
}

[Schol-R-LEA]

As has already been said yesterday, it is critical that you indent your code suitably, and use [code] or [highlight] tags around your code samples. The forum software does not retain indentation by default, and in order for the code to be readable, you need to use the [code] tags. You can do this manually, or by using the '#' button at the top of the editing window and pasting your code into the edit box that comes up.

#include<stdio.h>
#include<stdlib.h>
 
int main()
{
    int i, n;
    struct mode
    {
        int num; 
        struct mode * next;
    };
    struct mode *header, *last,  *temp, *present;
    header = NULL;
 
    printf("Enter the amount of people \n");
    scanf("%d", &n);
    for (i=1; i<n; i++)
    {
        temp = malloc(sizeof(struct mode));
        temp -> num = 1;
        temp -> next = NULL;
        if (i == 1) 
            header = temp;
        else 
            last-> next = temp; 
        last = temp;
    }
    present = header; 
    while (present != NULL)  
    {
        printf("%6d", present->num);
        temp = present;
        present = present ->next;
        free(temp);
    }
    return 0;
}

As a minor quibble, I would move the struct definition out of the main() function; having it in main() limits the visibility of the type, meaning you can't extract the code from main() into separate functions - something I would recommend you do as well.

As for the specific problem you are having, the main reason it is occurring is because you are always assigning temp->num as 1. You presumably meant to set it to i instead.