console.clear(); function isUniqueLinear(arr) { const seenValues = {}; for (let i = 0; i < arr.length; i++) { if (seenValues[arr[i]]) { return false; } else { seenValues[arr[i]] = true; } } return true; } let smallDuplicate = [1, 4, 6, 10, 4]; let largeDuplicate = _.range(3500).concat(5).concat(_.range(10000, 3510)); let smallUnique = [1, 4, 5, 10, 52]; let largeUnique = _.range(10000); console.log(isUniqueLinear(smallDuplicate)) console.log(isUniqueLinear(largeDuplicate)) console.log(isUniqueLinear(smallUnique)) console.log(isUniqueLinear(largeUnique))