/* Compile with:
 * c++ -O3 -Wall -pedantic -o additive-stream additive-stream.cc \
 *			-lreadline -lcurses
 *
 * It should be pretty obvious what you need to uncomment
 * to see the actual stream itself, if you want it.
 */
#include <stdio.h>
#include <stdlib.h>
#include <readline/readline.h>
#include <readline/history.h>
#include <curses.h>
#include <term.h>

char * readline (const char *prompt);

int main( int argc,
	char **argv ) {

	int	length, i, j, next;
	double	loopCount;	// must be type double to count very very high!
	int	* list;
	int	* originalList;
	int	foundLoop;

	printf("length = %d\n", argc - 1);
	if (argc == 1) {
		printf("\n");
		printf("Call with a sequence of digits, e.g.:\n");
		printf("  %s 1 2 3 4\n", argv[0]);
		printf("\n");
		exit(1);
	}

	list = (int *) malloc((argc - 1)*sizeof(int));
	originalList = (int *) malloc((argc - 1)*sizeof(int));
	for (i = 1; i < argc; i++) {
		list[i-1] = atoi(argv[i])%10;
	}
	length = argc - 1;
	for (i = 0; i < length; i++) {
		printf("%d", list[i]);
		originalList[i] = list[i];
	}
	printf("\n\n");

	/* Uncomment these three lines to first print the input seed */
//	for (i = 0; i < length; i++) {
//		printf("%d", list[i]);
//	}
	foundLoop = 0;
	loopCount = 0.0;
	while(foundLoop == 0) {
		next = (list[0] + list[1]) % 10;
		for (i = 0; i < length-1; i++) {
			list[i] = list[i+1];
		}
		list[length-1] = next;
		/* And uncomment these two lines to see the generated digits */
//		printf("%d", next);
//		fflush(stdout);
		foundLoop = 1;
		j = 0;
		for (i = 0; i < length; i++) {
			if (list[i] != originalList[i]) {
				foundLoop = 0;
				j++;
			}
		}
		loopCount++;
		if (j == 1) {
			for (i = 0; i < length; i++) {
				printf("%d", list[i]);
			}
			printf(" => close hit at position %20.0f\n", loopCount);
		}
	}

	printf("\n Found loop at position %.0f\n", loopCount);
	
	exit(0);
}