/* 	Example 9.3: Sequential search
	Algorithm: Gilberg and Forouzan, p. 40
	Modification: Peter Brusilovsky
	
	Reads array from the st input, then requests element
	to be found until it can be found.
*/

#include <stdio.h>
#define N 7 /* dimension of the array */
int readarray(int ar[], int n);
int ordSeqSearch(int list[], int last, int target);

main() {

	/* declare an array */
	int testarray[N];
	int mytarget, index;
	
	/* read data */
	readarray(testarray, N);
	do {
		/* get target */
		printf("Enter target: ");
		scanf("%d", &mytarget);
		
		/* find */
		if ((index = ordSeqSearch(testarray, N, mytarget)) == -1 ) 
			printf("Target %d not found\n", mytarget);
		else 
			printf("Target %d is located at index %d\n", mytarget, index);
	} while(index == -1); /* loop ends when the requested element found */
	return 0;
}

/* array input */
int readarray(int ar[], int n_of_elements) {
	int i;
	for (i = 0; i < n_of_elements; ++i) {
		printf("%d> ", i);
		scanf("%d", &ar[i]);
	}
	return 0;
}


/* finding index of the array element with the target value
	returns -1 if not found */
int ordSeqSearch(int list[], int last, int target) {
	int looker = 0;
	
	if (target > list[last-1])
		return -1;
	
	while (target > list[looker])
		looker++;
	
	/* the loop ended either because target < list[looker] or target == list[looker] */
	if (target < list[looker])  /* i.e., if we got to the end of list with no success */
		return -1;
	else /* found */
		return looker;
}