3396. Minimum Number of Operations to Make Elements in Array Distinct - Easy
                
                前往題目
            
            想法
- 用Set暴力解
思路
- 從後面比較快,每次往前一位就加入set,同時判斷是否已經有
- 如果已經重複就可以直接算出需要幾次operation
Code
class Solution {
    public int minimumOperations(int[] nums) {
        Set<Integer> set = new HashSet();
        for (int i = nums.length - 1; i >= 0; --i) {
            // Found duplicate
            if (!set.add(nums[i])) {
                return i / 3 + 1; // Cal. operations
            }
        }
        return 0;
    }
}3396. Minimum Number of Operations to Make Elements in Array Distinct - Easy
      https://f88083.github.io/2025/04/08/3396-Minimum-Number-of-Operations-to-Make-Elements-in-Array-Distinct-Easy/