Sorting Algorithms Tech Talk
Basic sorting algorithms and queue implementation (hopefully)
public class SortingAlgorithms {
// Bubble Sort Algorithm
public static void bubbleSort(int[] arr) {
int n = arr.length;
for (int i = 0; i < n - 1; i++) {
for (int j = 0; j < n - i - 1; j++) {
if (arr[j] > arr[j + 1]) {
int temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
}
}
// Selection Sort Algorithm
public static void selectionSort(int[] arr) {
int n = arr.length;
for (int i = 0; i < n - 1; i++) {
int minIndex = i;
for (int j = i + 1; j < n; j++) {
if (arr[j] < arr[minIndex]) {
minIndex = j;
}
}
int temp = arr[minIndex];
arr[minIndex] = arr[i];
arr[i] = temp;
}
}
// Insertion Sort Algorithm
public static void insertionSort(int[] arr) {
int n = arr.length;
for (int i = 1; i < n; i++) { // start from 1
int key = arr[i];
int j = i - 1;
while (j >= 0 && arr[j] > key) {
arr[j + 1] = arr[j];
j--;
}
arr[j + 1] = key;
}
}
// Merge Sort Algorithm
public static void mergeSort(int[] arr) {
if (arr.length > 1) {
int mid = arr.length / 2;
int[] left = Arrays.copyOfRange(arr, 0, mid);
int[] right = Arrays.copyOfRange(arr, mid, arr.length);
mergeSort(left);
mergeSort(right);
int i = 0, j = 0, k = 0;
while (i < left.length && j < right.length) {
if (left[i] < right[j]) {
arr[k++] = left[i++];
} else {
arr[k++] = right[j++];
}
}
while (i < left.length) {
arr[k++] = left[i++];
}
while (j < right.length) {
arr[k++] = right[j++];
}
}
}
}
// try mergesort
int[] a = new int[]{5, 4, 3, 2, 1};
SortingAlgorithms.mergeSort(a);
System.out.println(Arrays.toString(a));
// try insertionsort
a = new int[]{5, 4, 3, 2, 1};
SortingAlgorithms.insertionSort(a);
System.out.println(Arrays.toString(a));
// try selectionsort
a = new int[]{5, 4, 3, 2, 1};
SortingAlgorithms.selectionSort(a);
System.out.println(Arrays.toString(a));
// try bubblesort
a = new int[]{5, 4, 3, 2, 1};
SortingAlgorithms.bubbleSort(a);
System.out.println(Arrays.toString(a));