2149. Rearrange Array Elements by Sign

 

Input: nums = [3,1,-2,-5,2,-4]
Output: [3,-2,1,-5,2,-4]
Explanation:
The positive integers in nums are [3,1,2]. The negative integers are [-2,-5,-4].
The only possible way to rearrange them such that they satisfy all conditions is [3,-2,1,-5,2,-4].

 Other ways such as [1,-2,2,-5,3,-4], [3,1,2,-2,-5,-4], [-2,3,-5,1,-4,2] are incorrect because 

they do not satisfy one or more conditions. 

class Solution {

public int[] rearrangeArray(int[] nums) {

int posIdx = 0;

int negIdx = 1;

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

for(int num : nums){

if(num > 0){

res[posIdx] = num;

posIdx += 2;

}else{

res[negIdx] = num;

negIdx += 2;

}

}

return res;

}

}