#include <iostream>
#include <vector>
#include <limits>
#include <cstdlib> // std::abs
/**
* Finds the minimum distance between two target values in an vector.
*
* @param vec Input vector.
* @param x First target value.
* @param y Second target value.
* @return Minimum distance between x and y.
* Returns -1 if either value does not exist or no valid pair is found.
*/
int findMinDistance(const std::vector<int>& vec, int x, int y)
{
int lastSeenIndex = -1;
int minDistance = std::numeric_limits<int>::max();
for (int i = 0; i < static_cast<int>(vec.size()); ++i)
{
// Check if current element matches either target value
if (vec[i] == x || vec[i] == y)
{
// If we've already seen one of the target values
if (lastSeenIndex != -1 &&
vec[i] != vec[lastSeenIndex])
{
minDistance = std::min(
minDistance,
std::abs(i - lastSeenIndex)
);
}
// Update latest occurrence
lastSeenIndex = i;
}
}
return (minDistance == std::numeric_limits<int>::max())
? -1
: minDistance;
}
int main()
{
std::vector<int> vec = {2, 3, 7, 3, 3, 4, 8, 8, 8, 11, 9, 1, 3};
int result = findMinDistance(vec, 3, 8);
if (result != -1) {
std::cout << "Minimum distance: " << result << '\n';
}
else {
std::cout << "No valid pair found.\n";
}
}
/*
run:
Minimum distance: 2
*/
