Question

How to find the minimum index of a repeating element in an array with C++

Answer 1

#include <iostream>
#include <unordered_set>

int findMininimumIndex(int arr[], int size) {
    int minIndex = -1;
 
    std::unordered_set<int> set;
 
    for (int i = size - 1; i >= 0; i--) {
        if (set.find(arr[i]) != set.end()) {
            minIndex = i;
        }
        else {
            set.insert(arr[i]);
        }
    }

    return minIndex;
}
 
int main()
{
    int arr[] = { 3, 7, 8, 6, 9, 1, 8, 8, 6, 1, 1, 8 };

    int size = sizeof(arr) / sizeof(arr[0]);
 
    std::cout << findMininimumIndex(arr, size);
}




/*
run:

2

*/

 

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