const array = [4, 3, -2, 0, 1];
selectionSort(array);
console.log("Array after sorting:  " + array);


// Function to swap two elements by assigning 
// the first to a temporary variable then
// reassigning the actual array elements
// This runs directly in the function and
// acts on the array in memory rather than returning
// a swapped array
function swap(array, firstIndex, secondIndex) {
	let temp = array[firstIndex];
	array[firstIndex] = array[secondIndex];
	array[secondIndex] = temp;
}

function indexOfMinimum(array, startIndex) {

	let minValue = array[startIndex];
	let minIndex = startIndex;
	
	// Loop through the "sub array" or array not including
	// the minIndex, because we know that one has already
	// been sorted
	// If the index in the loop is less than the minIndex, 
	// make it the minIndex instead
	for (let i = minIndex + 1; i < array.length; i++) {
		if (array[i] < minValue) {
			minIndex = i;
			minValue = array[i];
		}
	}
	
	// Return the minIndex so we can use it in the
	// actual sorting function
	return minIndex;
}

function selectionSort(array) {
	let startIndex = 0; // Start at 0
	
	// Loop through the entire array, reassigning the
	// minIndex as we go
	// Swap the minIndex with i because minIndex will be
	// smaller - I'm not 100% on how that logic is
	// going down, TBQH
	for (let i = 0; i < array.length; i++) {
		startIndex++;
		minIndex = indexOfMinimum(array, i);
		swap(array, minIndex, i);
	}
};