Approach-6) Find Duplicates - Floyd's Hare & Tortoise Algorithm

find_duplicates_app_6.cpp

class Solution {
public:
    int findDuplicate(vector<int>& nums) {
        int tort = nums[0], hare = nums[0];

        do{
            tort = nums[tort];
            hare = nums[nums[hare]];
        }while(tort != hare);

        tort = nums[0];
        while(tort != hare){
            tort = nums[tort];
            hare = nums[hare];
        }

        return tort;
    }
};