442. 数组中重复的数据🔖数组🔖哈希表

• https://leetcode-cn.com/problems/find-all-duplicates-in-an-array/

暴力解法

/**

- @param {number[]} nums
- @return {number[]}
  \*/
  var findDuplicates = function(nums) {
  let arr =[]
  let result =[]
  nums.forEach(data=>{
  arr.includes(data) ? result.push(data) : arr.push(data)
  })
  return result
  };

哈希表

/\*\*
- @param {number[]} nums
- @return {number[]}
  \*/
  var findDuplicates = function(nums) {
  const map = new Map()
  const arr = []

for(let i = 0; i < nums.length; i++) {
if (map.has(nums[i])) {
arr.push(nums[i])
map.delete(nums[i])
} else {
map.set(nums[i])
}
}

return arr
};