Sorting
.sort()
Selection Sort
class Solution {
void sort(int arr[]) {
int n = arr.length;
// One by one move boundary of unsorted subarray
for (int i = 0; i < n - 1; i++) {
// Find the minimum element in unsorted array
int min_idx = i;
for (int j = i + 1; j < n; j++)
if (arr[j] < arr[min_idx])
min_idx = j;
// Swap the found minimum element with the first
// element
int temp = arr[min_idx];
arr[min_idx] = arr[i];
arr[i] = temp;
}
}
// Prints the array
void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
// Driver code to test above
public static void main(String[] args) {
Solution ob = new Solution();
int arr[] = { 64, 25, 12, 22, 11 };
ob.sort(arr);
System.out.println("Sorted array");
ob.printArray(arr);
}
}C programming
#include <stdio.h>
#include <stdlib.h>
int main() {
int N = 20;
int arr[N];
for(int i=0; i<N; i++) {
arr[i] = rand()%100;
}
for(int i = 0; i<N; i++) {
printf("%d ", arr[i]);
}
printf("\n");
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;
}
for(int i = 0; i<N; i++) {
printf("%d ", arr[i]);
}
printf("\n");
}Insertion Sort
class Solution {
static void sort(int arr[]) {
int n = arr.length;
for (int i = 1; i < n; ++i) {
int key = arr[i];
int j = i - 1;
while (j >= 0 && arr[j] > key) {
arr[j + 1] = arr[j];
j = j - 1;
}
arr[j + 1] = key;
arr_printer(arr);
}
}
static void arr_printer(int[] arr) {
for (int key : arr) {
System.out.print(key + " ");
}
System.out.print("\n");
}
static void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
public static void main(String[] args) {
int arr[] = { 13, 12, 11, 10, 6, 5 };
sort(arr);
printArray(arr);
}
}Quick Sort
class Solution {
int partition(int arr[], int low, int high) {
int pivot = arr[high];
// index of smaller element
int i = (low - 1);
for (int j = low; j < high; j++) {
// If current element is smaller than the pivot
if (arr[j] < pivot) {
i++;
int temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}
}
// swap arr[i+1] and arr[high] (or pivot)
int temp = arr[i + 1];
arr[i + 1] = arr[high];
arr[high] = temp;
return i + 1;
}
void sort(int arr[], int low, int high) {
if (low < high) {
int pi = partition(arr, low, high);
sort(arr, low, pi - 1);
sort(arr, pi + 1, high);
}
}
static void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
// Driver program
public static void main(String[] args) {
int arr[] = { 10, 7, 8, 9, 1, 5 };
int n = arr.length;
Solution ob = new Solution();
ob.sort(arr, 0, n - 1);
System.out.println("sorted array");
printArray(arr);
}
}Merge Sort
class Solution {
void merge(int arr[], int l, int m, int r) {
// Find sizes of two subarrays to be merged
int n1 = m - l + 1;
int n2 = r - m;
/* Create temp arrays */
int L[] = new int[n1];
int R[] = new int[n2];
/* Copy data to temp arrays */
for (int i = 0; i < n1; ++i)
L[i] = arr[l + i];
for (int j = 0; j < n2; ++j)
R[j] = arr[m + 1 + j];
/* Merge the temp arrays */
// Initial indexes of first and second subarrays
int i = 0, j = 0;
// Initial index of merged subarry array
int k = l;
while (i < n1 && j < n2) {
if (L[i] <= R[j]) {
arr[k] = L[i];
i++;
} else {
arr[k] = R[j];
j++;
}
k++;
}
/* Copy remaining elements of L[] if any */
while (i < n1) {
arr[k] = L[i];
i++;
k++;
}
/* Copy remaining elements of R[] if any */
while (j < n2) {
arr[k] = R[j];
j++;
k++;
}
}
// Main function that sorts arr[l..r] using
// merge()
void sort(int arr[], int l, int r) {
if (l < r) {
// Find the middle point
int m = (l + r) / 2;
// Sort first and second halves
sort(arr, l, m);
sort(arr, m + 1, r);
// Merge the sorted halves
merge(arr, l, m, r);
}
}
/* A utility function to print array of size n */
static void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
// Driver code
public static void main(String[] args) {
int arr[] = { 12, 11, 13, 5, 6, 7 };
System.out.println("Given Array");
printArray(arr);
Solution ob = new Solution();
ob.sort(arr, 0, arr.length - 1);
System.out.println("\nSorted array");
printArray(arr);
}
}Bubble Sort
class Solution {
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]) {
// swap arr[j+1] and arr[j]
int temp = arr[j];
arr[j] = arr[j + 1];
arr[j + 1] = temp;
}
}
/* Prints the array */
void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
// Driver method to test above
public static void main(String[] args) {
Solution ob = new Solution();
int arr[] = { 64, 34, 25, 12, 22, 11, 90 };
ob.bubbleSort(arr);
System.out.println("Sorted array");
ob.printArray(arr);
}
}C Programming
#include <stdio.h>
#include <stdlib.h>
int main() {
int N = 20;
int arr[N];
for (int i = 0; i < N; i++) {
arr[i] = rand() % 100;
printf("%d ", arr[i]);
}
printf("\n");
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 + 1];
arr[j + 1] = arr[j];
arr[j] = temp;
}
}
}
for (int i = 0; i < N; i++) {
printf("%d ", arr[i]);
}
}Radix Sort
import java.util.*;
class Solution {
static int getMax(int arr[], int n) {
int mx = arr[0];
for (int i = 1; i < n; i++)
if (arr[i] > mx)
mx = arr[i];
return mx;
}
// A function to do counting sort of arr[] according to
// the digit represented by exp.
static void countSort(int arr[], int n, int exp) {
int output[] = new int[n]; // output array
int i;
int count[] = new int[10];
Arrays.fill(count, 0);
// Store count of occurrences in count[]
for (i = 0; i < n; i++)
count[(arr[i] / exp) % 10]++;
// Change count[i] so that count[i] now contains
// actual position of this digit in output[]
for (i = 1; i < 10; i++)
count[i] += count[i - 1];
// Build the output array
for (i = n - 1; i >= 0; i--) {
output[count[(arr[i] / exp) % 10] - 1] = arr[i];
count[(arr[i] / exp) % 10]--;
}
// Copy the output array to arr[], so that arr[] now
// contains sorted numbers according to curent digit
for (i = 0; i < n; i++)
arr[i] = output[i];
}
// The main function to that sorts arr[] of size n using
// Radix Sort
static void radixsort(int arr[], int n) {
// Find the maximum number to know number of digits
int m = getMax(arr, n);
// Do counting sort for every digit. Note that
// instead of passing digit number, exp is passed.
// exp is 10^i where i is current digit number
for (int exp = 1; m / exp > 0; exp *= 10)
countSort(arr, n, exp);
}
// A utility function to print an array
static void print(int arr[], int n) {
for (int i = 0; i < n; i++)
System.out.print(arr[i] + " ");
}
/* Driver Code */
public static void main(String[] args) {
int arr[] = { 170, 45, 75, 90, 802, 24, 2, 66 };
int n = arr.length;
// Function Call
radixsort(arr, n);
print(arr, n);
}
}Bucket Sort
import java.util.*;
import java.util.Collections;
class Solution {
// Function to sort arr[] of size n
// using bucket sort
static void bucketSort(float arr[], int n) {
if (n <= 0)
return;
// 1) Create n empty buckets
@SuppressWarnings("unchecked")
Vector<Float>[] buckets = new Vector[n];
for (int i = 0; i < n; i++) {
buckets[i] = new Vector<Float>();
}
// 2) Put array elements in different buckets
for (int i = 0; i < n; i++) {
float idx = arr[i] * n;
buckets[(int) idx].add(arr[i]);
}
// 3) Sort individual buckets
for (int i = 0; i < n; i++) {
Collections.sort(buckets[i]);
}
// 4) Concatenate all buckets into arr[]
int index = 0;
for (int i = 0; i < n; i++) {
for (int j = 0; j < buckets[i].size(); j++) {
arr[index++] = buckets[i].get(j);
}
}
}
// Driver code
public static void main(String args[]) {
float arr[] = { (float) 0.897, (float) 0.565,
(float) 0.656, (float) 0.1234,
(float) 0.665, (float) 0.3434 };
int n = arr.length;
bucketSort(arr, n);
System.out.println("Sorted array is ");
for (float el : arr) {
System.out.print(el + " ");
}
}
}
Heap Sort
class Solution {
public void sort(int arr[]) {
int n = arr.length;
// Build heap (rearrange array)
for (int i = n / 2 - 1; i >= 0; i--)
heapify(arr, n, i);
// One by one extract an element from heap
for (int i = n - 1; i > 0; i--) {
// Move current root to end
int temp = arr[0];
arr[0] = arr[i];
arr[i] = temp;
// call max heapify on the reduced heap
heapify(arr, i, 0);
}
}
// To heapify a subtree rooted with node i which is
// an index in arr[]. n is size of heap
void heapify(int arr[], int n, int i) {
int largest = i; // Initialize largest as root
int l = 2 * i + 1; // left = 2*i + 1
int r = 2 * i + 2; // right = 2*i + 2
// If left child is larger than root
if (l < n && arr[l] > arr[largest])
largest = l;
// If right child is larger than largest so far
if (r < n && arr[r] > arr[largest])
largest = r;
// If largest is not root
if (largest != i) {
int swap = arr[i];
arr[i] = arr[largest];
arr[largest] = swap;
// Recursively heapify the affected sub-tree
heapify(arr, n, largest);
}
}
/* A utility function to print array of size n */
static void printArray(int arr[]) {
int n = arr.length;
for (int i = 0; i < n; ++i)
System.out.print(arr[i] + " ");
System.out.println();
}
// Driver code
public static void main(String[] args) {
int arr[] = { 12, 11, 13, 5, 6, 7 };
int n = arr.length;
Solution ob = new Solution();
ob.sort(arr);
System.out.println("Sorted array is");
printArray(arr);
}
}Last updated
