SOURCE

function th(fn, time) {
    let flag = true
    return function () {
        if(!flag){
            return
        }
        flag = false
        setTimeout(() => {
            fn()
            flag = true
        },time)
    }
}


const arr = [1, 2, 3, 4, 1,3, 6,8,91,12,4]

function maxLength( arr ) {
   const len = arr.length
   let repeatIndex = -1
   let maxLength = 0
   for(let i = 0; i < len; i++) {
       let itemA = arr[i]
       for(let k = i - 1; k >= 0; k--) {
           let itemB = arr[k]
           if (itemA === itemB) {
               if (repeatIndex < k) {
                    repeatIndex = k
               }
               break
           }
       }

       if (maxLength < i - repeatIndex) {
           maxLength = i - repeatIndex
       }
   }

   return maxLength
}

console.log('maxLength', maxLength(
[1,2,3,1,2,3,2,2]
))