function arrayPreviousLess(nums) {
    // Double for-loop: O(N^2) time complexity O(1) space
    for (let i = nums.length - 1; i >= 0; i--) {
        for (let j = i - 1; j >= 0; j--) {
            if (nums[j] < nums[i]) {
                nums[i] = nums[j]
                break
            } else if (j == 0) {
                nums[i] = -1
            }
        }
    }
    nums[0] = -1 // no numbers to left, final step after loop
    return nums
}



/**
* Test Suite 
*/
describe('arrayPreviousLess()', () => {
    it('shift previous postions from the left to a smaller value or store -1', () => {
        // arrange
        const nums = [3, 5, 2, 4, 5];
        
        // act
        const result = arrayPreviousLess(nums);

        // log
        console.log("result: ", result);
        
        // assert
        expect(result).toEqual([-1, 3, -1, 2, 4]);
    });
});