#pragma once
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
/* definiramo jezik - ZAČETEK */
#define J_0			"zero"
#define J_1			"one"
#define J_2			"two"
#define J_3			"three"
#define J_4			"four"
#define J_5			"five"
#define J_6			"six"
#define J_7			"seven"
#define J_8			"eight"
#define J_9			"nine"
#define J_10		"ten"
#define J_11		"eleven"
#define J_12		"twelve"
#define J_13		"thirteen"
#define J_14		"fourteen"
#define J_15		"fiveteen"
#define J_16		"sixteen"
#define J_17		"seventeen"
#define J_18		"eighteen"
#define J_19		"nineteen"
#define J_20		"twenty"
#define J_30		"thirty"
#define J_40		"forty"
#define J_50		"fifty"
#define J_60		"sixty"
#define J_70		"seventy"
#define J_80		"eighty"
#define J_90		"ninety"
#define J_1h		"hundred"
#define J_1k		"thousand"
#define J_1M		"million"
#define J_1G		"billion"
#define J_1T		"trillion"
#define J_AND		"and"
#define J_EMPTY	""
/* definiramo jezik - KONEC */
#define MX_NS_L	1337 
/* angnum : size_t (število zapisanih bajtov, -1 ob propadu sveta)
 *	n: lluint: številka, ki naj jo zapišemo
 *	s: pointer to allocatanega spomina, kamor zapišemo string
 *	l: število bajtov allocatanega spomina za string, IZključno zadnjega '\0'
 * alocirati morate vsaj en bajt več od l
 * string bo mogoče avtomatsko null terminiran, vseeno ga raje dajte še sami */
char * j_enice[] = { J_EMPTY, J_1, J_2, J_3, J_4, J_5, J_6, J_7, J_8, J_9, J_10, J_11, J_12, J_13, J_14, J_15, J_16, J_17, J_18, J_19, J_20 };
char * j_power[] = { J_EMPTY, J_1k, J_1M, J_1G, J_1T };
char * j_desetice[] = { J_EMPTY, J_10, J_20, J_30, J_40, J_50, J_60, J_70, J_80, J_90 };

unsigned long long int na(unsigned long long int a, unsigned long long int b) {
	unsigned long long int c = 1; /* jebeš math.h ke nima funkcije za intager */
	for (; b > 0; b--) {					/* potenciranje															*/
		c = c * a;
	}
	return c;
}

size_t angnum (unsigned long long int n, char * s, int l) {
	unsigned int i = 0; // Index Iteracij
	int z = 0; // Zapisanih
	if (n <= 20) { // "thirteen", namesto 0 je prazen string 
		z = snprintf(s, l, "%s", j_enice[n]);
		fprintf(stderr, "z = %d, l = %d, s = %s, n = %llu\n", z, l, s, n);
		return z;
	}
	if (n <= 99) { // && n > 20 // "forty-one" ali "thirty"
		z = snprintf(s, l, "%s", j_desetice[n / 10]); // intdiv je floor
		if (z < l && n % 10 != 0) s[z++] = '-';
		return z + (n % 10 != 0 ? snprintf(s+z, l-z, "%s", j_enice[n % 10]) : 0);
	}
 	if (n <= 999) { // && n > 99
		z = snprintf(s, l, "%s ", j_enice[n/100]); // "one "
		z = z + snprintf(s+z, l-z, "%s", J_1h); // "hundred"
		if (n % 100 != 0) {
			if (z < l) s[z++] = ' ';
			z = z + snprintf(s+z, l-z, "%s ", J_AND); // "and "
			return z + angnum(n-(n/100)*100, s+z, l-z);
		} else {
			return z;
		}
	} // sedaj je n > 99 && n < 1e21
	for (i = 3; i <= 21; i=i+3) // sedaj iščemo največjo tisočico
		if (n / na(10, i) <= 999) // zadnja tisočica
			break;
	z = angnum((n/na(10, i)), s, l-z); // "three hundred and forty-two"
	fprintf(stderr, "-z = %d, l = %d, s = %s, n = %llu\n", z, l, s, n);
	z = z + snprintf(s+z, l-z, " %s", j_power[i/3]); // "million"
	fprintf(stderr, "xz = %d, l = %d, s = %s, n = %llu\n", z, l, s, n);
	if (n-(n/na(i, 10)) > 0) {
		fprintf(stderr, "pz = %d, l = %d, s = %s, n = %llu\n", z, l, s, n);
		if (z < l) s[z++] = ' ';
		if (z < l) s[z++] = 'a';
		if (z < l) s[z++] = 'n';
		if (z < l) s[z++] = 'd';
		if (z < l) s[z++] = ' ';
		fprintf(stderr, "qz = %d, l = %d, s = %s, n = %llu\n", z, l, s, n);
		z = z + angnum(n-(n/na(10, i)*na(10, i)), s+z, l-z);
		fprintf(stderr, "zz = %d, l = %d, s = %s, n = %llu\n", z, l, s, n);
	}
	return z;
}
int main (int argc, char ** argv) {
	if (argc != 1+1) {
		fprintf(stderr, "uporaba: %s <stevilka>\nprimer, ki napiše \"four hundred and twenty\": %s 420\n", argv[0], argv[0]);
		return 1;
	}
	unsigned long long int n = strtoll(argv[1], NULL, 10);
	char * s = malloc(sizeof(char)*MX_NS_L);
	s[angnum(n, s, MX_NS_L-1)] = '\0';
	fprintf(stdout, "%s\n", s);
	return 0;
}