Remove-Duplicates-from-Sorted-Array/C++ at main · vinayak302004/Remove-Duplicates-from-Sorted-Array · GitHub

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# C++

1. Brute-Force Approach :

class Solution {
public:
    int removeDuplicates(std::vector<int>& nums) {
        int k = 1, n = nums.size();
        for (int i = 1; i < n; ++i) {
            if (nums[i - 1] != nums[i]) {
                nums[k] = nums[i];
                ++k;
            }
        }
        return k;
    }
};

2. Optimal Approach :

class Solution {
public:
    int removeDuplicates(std::vector<int>& nums) {
        std::unordered_set<int> set;
        int k = 0;
        for (int num : nums) {
            if (set.insert(num).second) {
                nums[k++] = num;
            }
        }
        return k;
    }
};