/**

* @filename findShortestSubArray.js

* @author 56

* @description https://leetcode-cn.com/problems/degree-of-an-array/

*/

/**

* 1. 题目要求寻找到相同度的最短子序列. 可转换为 求出现次数最多的数字的 起始位置和终点位置.

* @param {number[]} nums

* @return {number}

*/

var findShortestSubArray = function (nums) {

const len = nums.length

if (len === 1) return 1

let maxArr = [nums[0]]

const map = { [maxArr[0]]: { count: 1, range: [0, 0] } }

for (let i = 1; i < len; i++) {

const num = nums[i]

let obj

const maxCount = map[maxArr[0]].count

if (map[num]) {

obj = map[num]

obj.count++

obj.range[1] = i

} else {

obj = { count: 1, range: [i, i] }

map[num] = obj

}

if (obj.count > maxCount) maxArr = [num]

else if (obj.count === maxCount) maxArr.push(num)

}

let count = len

for (let i = 0, mLen = maxArr.length; i < mLen; i++) {

const range = map[maxArr[i]].range

const l = range[1] - range[0] + 1

if (l < count) count = l

}

return count

}

console.info(findShortestSubArray([1, 2, 2, 3, 1, 4, 2]))

console.info(findShortestSubArray([1, 2, 2, 3, 1]))