#define CATCH_CONFIG_MAIN

#include "catch.hpp"

#include <vector>

#include <unordered_set>

#include <limits>

using namespace std;

int firstRepeating(std::vector<int> & arr) {

std::unordered_set<int> arrSet;

int min = -1;

int arrSize = (int) arr.size();

for ( int i = arrSize -1; i >= 0; i--) {

if ( arrSet.find(arr[i]) != arrSet.end()) {

min = i;

} else {

arrSet.insert(arr[i]);

}

}

if ( min != -1 ) {

return arr[min];

} else {

return std::numeric_limits<int>::min();

}

}

TEST_CASE("Find first repeat 1"){

vector<int> arr1{234, 453465, 234, 6345, 14123, 624, 44, 34, 26, 7345 };

REQUIRE( firstRepeating(arr1) == 234 );

}

TEST_CASE("Find first repeat 2"){

vector<int> arr1{234, 453465, 6345, 14123, 624, 44, 34, 26, 7345 };

int theLimit = std::numeric_limits<int>::min();

REQUIRE( firstRepeating(arr1) == theLimit );

}

TEST_CASE("Find first repeat 3"){

vector<int> arr1;

for(int i = 0; i < 1000; i++){

if(i == 44){

arr1.push_back(44);

}

arr1.push_back(i);

}

REQUIRE( firstRepeating(arr1) == 44 );

}