Finding closest number to 0

Question

I am trying to troubleshoot a program in Java.

Requirements: Need to find the closest value to zero in an Array. In the Array if the values are like 1 and -1 the closest should be the positive value.

public class CloseToZero {    
    public static void main(String[] args) {    
        int[] data = {2,3,-2};    
        int curr = 0;    
        int near = data[0];     
        // find the element nearest to zero    
        for ( int i=0; i < data.length; i++ ){    
            curr = data[i] * data[i];     
            if ( curr <= (near * near) )  {     
                near = data[i]; 
            }     
        }    
        System.out.println( near );    
    }    
}

Answer 1

This will do it in O(n) time:

int[] arr = {1,4,5,6,7,-1};

int closestIndex = 0;
int diff = Integer.MAX_VALUE;
for (int i = 0; i < arr.length; ++i) {
    int abs = Math.abs(arr[i]);
    if (abs < diff) {
        closestIndex = i;
        diff = abs;
    } else if (abs == diff && arr[i] > 0 && arr[closestIndex] < 0) {
        //same distance to zero but positive 
        closestIndex =i;
    }
}   
System.out.println(arr[closestIndex ]);

Answer 2

Just add zero to this list.

Then sort the list

Arrays.sort(data);

then grab the number before or after the zero and pick the minimum one greater than zero

Answer 3

If you are using java8:

import static java.lang.Math.abs;
import static java.lang.Math.max;

public class CloseToZero {
    public static void main(String[] args) {
        int[] str = {2,3,-2};
        Arrays.stream(str).filter(i -> i != 0)
                .reduce((a, b) -> abs(a) < abs(b) ? a : (abs(a) == abs(b) ? max(a, b) : b))
                .ifPresent(System.out::println);
    }
}