//https://leetcode.com/problems/squares-of-a-sorted-array/

import java.util.Arrays;

public class SortedSquares {

//Approach

//We can solve by squaring all and sorting which takes O(nlogn)

//Better approach is having 2 ptrs

//strt and end ptr comparing squares with each other and filling the result array

//O(n)

//sqaring all positives and all negatives are corner cases as increasing order for neg cases is decreasing order of squares

public static int[] sortedSquares(int[] nums) {

int negPtr=0,posPtr=nums.length-1,resPtr=nums.length-1;

int[] res=new int[nums.length];

while(negPtr<=posPtr) {

int negSqr=nums[negPtr]*nums[negPtr];

int posSqr=nums[posPtr]*nums[posPtr];

if(negSqr>posSqr) {

res[resPtr--]=negSqr;

negPtr++;

} else {

res[resPtr--]=posSqr;

posPtr--;

}

}

return res;

}

public static void main(String[] args) {

Arrays.stream(sortedSquares(new int[] {-10,-4,-3,-1,0})).forEach(System.out::println);

}

}