Split in C example with variable length string

split.c

#include <stdio.h>
#include <string.h>
#include <cs50.h>
#include <stdlib.h>

int main(void){
	string s = get_string(); // replace this for char * and read to it in an normal way
	int n = strlen(s), number_words = 0;
	char *c; 
	//c = malloc((5+1)*sizeof *c);	
//	strncpy(c, s, 5);
//	c[5] = '\0';
//	printf("%s\n", c);
//	free(c);
	for(int i = 0; i < n; i++){
		if(s[i] == ' ')
			number_words++;
	}

	number_words++;
	// Split
	int j = 0, k = 0;
	char ** words = (char **) malloc(number_words * sizeof c); 
	char *x;
	for(int i = 0; i < n; i++){

		if(s[i] == ' '){	
			x = malloc((i-k+1) * sizeof *c);
			strncpy(x, s+k, (i-k));
			x[i-k] = '\0';
			//printf("%s\n", x);
			words[j] = x;
			j++;
			k = i+1;

		}
	}
	k--;
	x = malloc((n-k) * sizeof *c);
	strncpy(x, s+k+1, (n-k-1));
	x[n-k-1] = '\0';
	//printf("%s\n", x);
	words[j] = x;
	j++;
	

	
	for(int i = 0; i < number_words; i++){
		printf("%s\n", words[i]);
		free(words[i]);
	}	
	free(words);
	free(c);
}