Thread: Longest Index

I have a second Q.
this time I wroth somthing, and it's working!
but again I can't reach the reqeirment:
"you are not allowed to change array; you are not allowed to use more than 1 additional (helper) functions(recursive and no recursive) that can be reached from longestIndex."

This is the ass description:
"Example: Consider arr={0,5,1,1,2}. Indices 0,2 and 3 are well-placed:
• Index 0 is well-placed since P0=0.
• Index 1 is not well-placed, since P1=5>1. Since all elements are positive, it’s impossible to find a sequence starting at index 1 that can be summed to 1.
• Index 2 is well-placed since P2+P3= 2.
• Index 3 is well-placed, since P3 + P4 = 3.
• Index 4 is not well-placed: We can’t find a sequence starting at index that can be summed to 4 – that’s because P4 is the last element in the array, and it’s only 2.

We define ‘well-placed length’ of a well-placed index to be j-i+1 – The length of the sequence that when summed shows that the index is well placed. It is possible an index is well-placed with more than a single sequence of elements. The ‘well-placed length’ in that case is the maximal length of the various sequences defining the index as ‘well-placed’.

"Example: Looking at previous example:
• Index 0 well-placed length is 1 (i=0, j=0, j-i+1 = 1).
• Index 2 well-placed length is 2 (i=2, j=3, j-i+1 = 2).
• Index 3 well-placed length is 2 (i=3, j=4, j-i+1 = 2).
• For indices 1 and 4, well-placed length is not defined, since the indices are not well-placed.
• Consider arr= {0,5,1,1,2,0} – index 3 well-placed length is now 3 (i=3, j=5, j-i+1=3). Another sequence that defines index 3 as well-placed is (i=3, j=4, j-i+1=2) as before, but we’ve defined well-placed length to be the maximal value for the index.


Function Prototype:
int longestIndex(int arr[], int length)[])"

my code is:

Code:

#include <stdio.h>
#define INPUT_LEN 256

int longestIndex(int arr[], int length);
void scan2(int arr[] ,int length, int beginLength);
int count(int arr[],int length,int beginLength, int sum ,int i,int biggestSum ,int chekIndex);
int chekZero(int arr[] , int length ,int place , int zeroCount);


void main(){

	int	 length;
	int  arr[INPUT_LEN];

	printf("Enter the length:\n");
	scanf("%d",&length);
	printf("Enter the array:\n");
	scan2(arr,length,0);
	printf("Output:\n");
	printf("%d\n\n",longestIndex(arr,length));
}
//Help Input recurcive func.
void scan2(int arr[] ,int length , int beginLength){
	if (beginLength > length-1) return;
	scanf("%d",&arr[beginLength]);
	scan2(arr,length,beginLength+1);
	return;
}

int longestIndex(int arr[], int length){
	return(count(arr,length,0,0,0,0,0));
}

int count(int arr[],int length,int beginLength, int sum ,int i,int biggestSum,int chekIndex){ 
	if (beginLength > length) return(biggestSum); 
	i++;
	sum += arr[beginLength];
	if (sum == chekIndex){
		if (biggestSum < i) 
			biggestSum = i;
			biggestSum += chekZero(arr,length,beginLength+1,0);
			beginLength = chekIndex; 
		return(count(arr,length,beginLength+1,0,0,biggestSum,chekIndex+1));
	}
	if (sum > chekIndex){
		beginLength = chekIndex;
		return(count(arr,length,beginLength+1,0,0,biggestSum,chekIndex+1));
	}
	if (sum < chekIndex){			
	return(count(arr,length,beginLength+1,sum,i,biggestSum,chekIndex));
	}
 return 0;		
}

int chekZero(int arr[] , int length ,int place , int zeroCount){
	if (place > length) return (zeroCount);
	if (arr[place] != 0) return (zeroCount);
	else{
		zeroCount++;
		return(chekZero(arr,length,place+1,zeroCount));
	}
}

I need some how to merge between count to chekZero, to stand the reqeirment.

This ass, is for practice recursion method.
so it's forbidden to use loops (for,while etc)