2475. Number of Unequal Triplets in Array

You are given a 0-indexed array of positive integers nums. Find the number of triplets (i, j, k) that meet the following conditions:

• 0 <= i < j < k < nums.length
• nums[i], nums[j], and nums[k] are pairwise distinct.

• In other words, nums[i] != nums[j], nums[i] != nums[k], and nums[j] != nums[k].

Return the number of triplets that meet the conditions.

class Solution {
public:
    int unequalTriplets(vector<int>& nums) {
        int res = 0;
        for(int  i = 0; i < nums.size(); i++) {
            for(int j = i+1; j < nums.size();  j++) {
                if(nums[i] == nums[j]) continue;
                for(int k = j + 1; k < nums.size(); k++) {
                    if(nums[i] == nums[k]) continue;
                    if(nums[k] == nums[j]) continue;
                    res += 1;
                }
            }
        }
        return res;
    }
};