Problem 23

  1#include<stdio.h>
  2#include<stdlib.h>
  3
  4struct sum_nums{
  5    int num;
  6    struct sum_nums * next;
  7};
  8
  9struct abundant_nums{
 10    int abundant_num;
 11    struct abundant_nums * next;
 12};
 13
 14struct abundant_nums * head = NULL;
 15struct sum_nums * first = NULL;
 16
 17void add_to_sum_nums(int num){
 18    if(first == NULL){
 19        first = malloc(sizeof(struct sum_nums));
 20        first->num = num;
 21        first->next = NULL;
 22    }
 23    else{
 24        struct sum_nums * temp = first;
 25        while(temp->next != NULL){
 26            temp = temp->next;
 27        }
 28        temp->next = malloc(sizeof(struct sum_nums));
 29        temp->next->num = num;
 30        temp->next->next = NULL;
 31    }
 32}
 33
 34void add_to_abundant(int num){
 35    if(head == NULL){
 36        head = malloc(sizeof(struct abundant_nums));
 37        head->abundant_num = num;
 38        head->next = NULL;
 39    }
 40    else{
 41        struct abundant_nums * temp = head;
 42        while(temp->next != NULL){
 43            temp = temp->next;
 44        }
 45        temp->next = malloc(sizeof(struct abundant_nums));
 46        temp->next->abundant_num = num;
 47        temp->next->next = NULL;
 48    }
 49}
 50void is_abundant(int num){
 51    int sum = 0;
 52    printf("Current number: %d", num);
 53    for(int i = 1; i < num -1; i++){
 54        if(num % i == 0){
 55            printf("%d\n\n", i);
 56            sum += i;
 57        }
 58    }
 59    if(sum > num){
 60        printf("%d is abundant\n\n", num);
 61        add_to_abundant(num);
 62    }
 63}
 64
 65
 66void can_be_written_as_sum(int num){
 67    struct abundant_nums * temp = head;
 68    struct abundant_nums * iterator;
 69    int is_sum = 0;
 70    while(temp != NULL && is_sum == 0){
 71        int difference = num - temp->abundant_num;
 72        if(difference > 0){
 73            iterator = temp->next;
 74            while(iterator != NULL && is_sum == 0){
 75                if(iterator->abundant_num == difference){
 76                    is_sum = 1;
 77                }
 78                iterator = iterator->next;
 79            }
 80        }
 81        temp = temp->next;
 82    }
 83    if(is_sum == 0){
 84        printf("\n%d cannot be written as sum", num);
 85        add_to_sum_nums(num);        
 86    }
 87}
 88
 89int get_sum(){
 90    int sum = 0;
 91    struct sum_nums * iterator = first;
 92    while(iterator != NULL){
 93        sum += iterator->num;
 94        iterator = iterator->next;
 95    }
 96    return sum;
 97}
 98
 99int main(){
100    for(int i = 12; i < 28123; i++){
101        is_abundant(i);
102    }
103
104    for(int i = 24; i < 30000; i++){
105        can_be_written_as_sum(i);
106    }
107
108    printf("Sum of nums %d\n", get_sum());
109}