26. Remove Duplicates from Sorted Array - cocoder39/coco39_LC GitHub Wiki

int removeDuplicates(vector<int>& nums) {
        int k = 0;
        for (int i = 0; i < nums.size(); i++) {
            if (i == 0 || nums[i] != nums[i - 1]) {
                nums[k++] = nums[i];
            }
        }
        return k;
    }

int removeDuplicates(vector<int>& nums) {
        unordered_set<int> st;
        int cnt = 0;
        for (int i = 0; i < nums.size(); i++) {
            auto it = st.find(nums[i]);
            if (it == st.end()) {
                nums[cnt++] = nums[i];
                st.insert(nums[i]);
            }
        }
        return cnt;
    }