There are many sorting algorithms, each has its own advantages and limitations.
Sorting is commonly used as the introductory problem in various Computer Science classes to showcase a range of algorithmic ideas.
Here are some examples of algorithms applied on arrays of integers and their animation to visualize how they work.
1. Bubble Sort
Algorithm:
function bubbleSort(arr){
var len = arr.length;
for (var i = len-1; i>=0; i--){
for(var j = 1; j<=i; j++){
if(arr[j-1]>arr[j]){
var temp = arr[j-1];
arr[j-1] = arr[j];
arr[j] = temp;
}
}
}
return arr;
}
2. Selection Sort
Algorithm:
function selectionSort(arr){
var minIdx, temp,
len = arr.length;
for(var i = 0; i < len; i++){
minIdx = i;
for(var j = i+1; j<len; j++){
if(arr[j]<arr[minIdx]){
minIdx = j;
}
}
temp = arr[i];
arr[i] = arr[minIdx];
arr[minIdx] = temp;
}
return arr;
}
3. Merge Sort
Algorithm:
function mergeSort(arr){
var len = arr.length;
if(len <2)
return arr;
var mid = Math.floor(len/2),
left = arr.slice(0,mid),
right =arr.slice(mid);
return merge(mergeSort(left),mergeSort(right));
}
function merge(left, right){
var result = [],
lLen = left.length,
rLen = right.length,
l = 0,
r = 0;
while(l < lLen && r < rLen){
if(left[l] < right[r]){
result.push(left[l++]);
}
else{
result.push(right[r++]);
}
}
return result.concat(left.slice(l)).concat(right.slice(r));
}
4. Quick Sort
Algorithm:
function quickSort(arr, left, right){
var len = arr.length,
pivot,
partitionIndex;
if(left < right){
pivot = right;
partitionIndex = partition(arr, pivot, left, right);
//sort left and right
quickSort(arr, left, partitionIndex - 1);
quickSort(arr, partitionIndex + 1, right);
}
return arr;
}
function partition(arr, pivot, left, right){
var pivotValue = arr[pivot],
partitionIndex = left;
for(var i = left; i < right; i++){
if(arr[i] < pivotValue){
swap(arr, i, partitionIndex);
partitionIndex++;
}
}
swap(arr, right, partitionIndex);
return partitionIndex;
}
function swap(arr, i, j){
var temp = arr[i];
arr[i] = arr[j];
arr[j] = temp;
}