42 -【leetcode】只出现一次的数字 II

[asdzxc01]

https://leetcode-cn.com/problems/single-number-ii/

[asdzxc01]

/**
    * @param {number[]} nums
    * @return {number}
    */
    var singleNumber = function (nums) {
      const myMap = new Map()
      for (let i = 0; i <= nums.length - 1; i++) {
        const value = nums[i]
        myMap.set(value, (myMap.get(value) || 0) + 1)
      }
      let res = 0
      console.log('myMap=', myMap)
      for (let [key, value] of myMap) {
        console.log('key,value=',key,value)
        if (value === 1) {
          res = key
        }
      }
      return res
    }

[xieshiyi]

/**
 * @param {number[]} nums
 * @return {number}
 */
var singleNumber = function(nums) {
    let map = {}
    for(num of nums) {
        map[num] = (map[num] || 0) + 1
    }
    for(num of nums) {
        if(map[num] === 1) {
            return num
        }
    }
};