c - linkedlist

c - linkedlist

 

store ordered number in linkedlist, no repeat.

 

 

code:

    linkedlist_test.c:

 

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

extern struct linkedlist {
	int num;
	struct linkedlist *pnext;
};

/**
 * add a num to ordered linkedlist, if it not exists yet,
 * 
 * @param num
 * 	the number to add
 * @param start
 * 	start of the linkedlist
 * 
 * @return
 * 	the start
 */
struct linkedlist *add(int num, struct linkedlist *start) {
	if(start == NULL) {
		start = (struct linkedlist *) malloc(sizeof(struct linkedlist));
		start->num = num;
		start->pnext = NULL;
	} else if((start->num) < num) {
		start->pnext = add(num, start->pnext);
	} else if((start->num) > num) {
		struct linkedlist *old_start = start;
		start = (struct linkedlist *) malloc(sizeof(struct linkedlist));
		start->num = num;
		start->pnext=old_start;
	}
		
	return start;
}

/**
 * print the linkedlist
 * 
 * @param start
 * 	start of the linkedlist
 * @param count
 	used to count elements
 */
void printll(struct linkedlist *start, int count){
	if(start != NULL) {
		count++;
		printf("%d, ",start->num);
		printll(start->pnext, count);
	} else {
		printf("\ntotal: %d\n",count);	
	}
}


int main() {
	int nums[] = {5,3,9,2,100,4,23,2,6,19,17,11,41,100,9,6,19}, i, n, count;
	struct linkedlist *start = NULL;
	n = sizeof(nums) / sizeof(nums[0]);
	for(i=0;i<n;i++) {
		start = add(nums[i], start);
	}
	count = 0;
	printll(start, count);
	return 1;
}