#145 · #2870 · Minimum Number of Operations to Make Array Empty(使数组为空的最少操作次数)

You are given an array nums of positive integers. In one operation, remove either two equal elements or three equal elements. Return the minimum number of operations to empty the array, or -1 if it is impossible. Constraints: 2 <= nums.length <= 10^5, 1 <= nums[i] <= 10^6.