问题：
输入数组[1,1,2,2,3,4]
希望输出：
3或者[3,4]
代码
function solution(arr,isMultiple=false) {
let result = isMultiple?[]:'not find',obj =[]
for (let i = arr.length - 1; i >= 0; i--) {
let val = arr[i]
if(obj[val] === undefined || obj[val] === null){
obj[val] = 1
} else {
obj[val] += 1
}
}
for (let i = 0; i < arr.length; i++) {
let val = arr[i]
if (obj[val] === 1) {
if (isMultiple) {
result.push(val)
}else{
result = val
break;
}
}
}
return result;
}
function run() {
console.log(solution([1,1,2,2,3,3,4,5,6]))
}
run()
