#include<iostream>
#include<cstring>
#include<cmath>
using namespace std;

struct place_contents {
	float x = 1000000, y = 1000000, z = 1000000;
	char contents[16] = "";
};

#define SIZE 100
// Have to say "struct place_conents" in C
place_contents entity_table[SIZE];

size_t coord_hash(float x, float y, float z){
	size_t hash_value = 13 * round(x) + 23 * round(y) + 29 * round(z);
	return hash_value % SIZE;
}

bool equal(place_contents *loc, float x, float y, float z){
	return round(x) == loc->x && round(y) == loc->y && round(z) == loc->z;
}	

const char* get_contents(float x, float y, float z){
	place_contents *found_thing = &entity_table[coord_hash(x, y, z)]; 
	while(!equal(found_thing, x, y, z) && found_thing->contents[0] != 0) {
		found_thing++;
		if(found_thing >= entity_table + SIZE)
			found_thing = entity_table;
	}
	if(found_thing->contents[0])
		return found_thing->contents;
	else
		return "Not found";
}

void set_contents(float x, float y, float z, const char* new_contents){
	place_contents *found_thing = &entity_table[coord_hash(x, y, z)];
	while(!equal(found_thing, x, y, z) && found_thing->contents[0] != 0) {
		found_thing++; // What if we hit the end of the table?
		if(found_thing >= entity_table + SIZE)
			found_thing = entity_table;
	}
	strncpy(found_thing->contents, new_contents, 16);
	found_thing->x = round(x);
	found_thing->y = round(y);
	found_thing->z = round(z);
}


int main(){
	set_contents(2.3, 4.1, 3.2, "A Goblin");
	set_contents(-2.0, 4.1, 3.2, "A Ogre");
	set_contents(2.3, 4.1, 5.2, "A good NPC");
	set_contents(2.3, 4.1, 10.1, "A bad NPC");

	cout << get_contents(2.2, 4.0, 5.1) << endl;
	cout << get_contents(2.2, 4.0, 10.1) << endl;
	cout << get_contents(1.0, 4.0, 5.1) << endl;
	cout << get_contents(2.1, 3.8, 2.9) << endl;

}