other.c

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

typedef struct{
	int i;
} junk_t;

junk_t * junk = { NULL };
int junk_length = 0;
int junk_used = 0;

void print_all();

void add(junk_t new_junk_city){
	
	printf("add!\n");
	
	if (junk_used == junk_length){
		junk_length += 2;
		junk = realloc(junk, (sizeof(char)) * junk_length);
		printf("resize up!\n");
	}
	
	junk[junk_used] = new_junk_city;
	
	junk_used++;
	print_all();
}

void del(int i){
	
	printf("delete %d!\n", junk[i].i);
	junk[i] = junk[junk_used -1];
	junk_used--;
	print_all();
}

void print_all(){
	printf("used: %2d / %2d\n", junk_used, junk_length);
	for(int i = 0; i < junk_length; i++)
		printf("junk[%d]: &%p\t%d\t%d\n", i, junk + i, junk[i].i, (i < junk_used));
	printf("\n");
}

int main(){
	
	print_all();
	
	junk_t a = { .i = 1 };
	
	for(int i = 0; i < 3; i++){
		a.i += i+2;
		add(a);
	}
	
	del(2);
	del(0);
	
	for(int i = 0; i < 3; i++){
		a.i += i+7;
		add(a);
	}
	
	del(1);
	
	print_all();
	
	free(junk);
	
	return 0;
}