function arrayPreviousLess(nums) {
    let array = [];
    
    nums.reverse().forEach((value, index) => {
        for (let i = index; i < nums.length; i++) {
            if (value > nums[i]) return array.unshift(nums[i]);   
        }
        array.unshift(-1)  
    });
    
    return array;
}



/**
* 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]);
    });
});