Pseudocode Examples
1. Linear Search
BEGIN LinearSearch(arr, target)
FOR i FROM 0 TO LENGTH(arr) - 1
IF arr[i] = target THEN
RETURN i
END IF
END FOR
RETURN -1
END LinearSearch
FOR i FROM 0 TO LENGTH(arr) - 1
IF arr[i] = target THEN
RETURN i
END IF
END FOR
RETURN -1
END LinearSearch
2. Binary Search
BEGIN BinarySearch(arr, target)
SET low = 0
SET high = LENGTH(arr) - 1
WHILE low <= high
SET mid = (low + high) / 2
IF arr[mid] = target THEN
RETURN mid
ELSE IF arr[mid] < target THEN
SET low = mid + 1
ELSE
SET high = mid - 1
END IF
END WHILE
RETURN -1
END BinarySearch
SET low = 0
SET high = LENGTH(arr) - 1
WHILE low <= high
SET mid = (low + high) / 2
IF arr[mid] = target THEN
RETURN mid
ELSE IF arr[mid] < target THEN
SET low = mid + 1
ELSE
SET high = mid - 1
END IF
END WHILE
RETURN -1
END BinarySearch
3. Bubble Sort
BEGIN BubbleSort(arr)
SET n = LENGTH(arr)
FOR i FROM 0 TO n - 1
FOR j FROM 0 TO n - i - 2
IF arr[j] > arr[j+1] THEN
SWAP arr[j] AND arr[j+1]
END IF
END FOR
END FOR
END BubbleSort
SET n = LENGTH(arr)
FOR i FROM 0 TO n - 1
FOR j FROM 0 TO n - i - 2
IF arr[j] > arr[j+1] THEN
SWAP arr[j] AND arr[j+1]
END IF
END FOR
END FOR
END BubbleSort
4. Selection Sort
BEGIN SelectionSort(arr)
SET n = LENGTH(arr)
FOR i FROM 0 TO n - 1
SET minIndex = i
FOR j FROM i+1 TO n - 1
IF arr[j] < arr[minIndex] THEN
SET minIndex = j
END IF
END FOR
SWAP arr[i] AND arr[minIndex]
END FOR
END SelectionSort
SET n = LENGTH(arr)
FOR i FROM 0 TO n - 1
SET minIndex = i
FOR j FROM i+1 TO n - 1
IF arr[j] < arr[minIndex] THEN
SET minIndex = j
END IF
END FOR
SWAP arr[i] AND arr[minIndex]
END FOR
END SelectionSort
5. Insertion Sort
BEGIN InsertionSort(arr)
SET n = LENGTH(arr)
FOR i FROM 1 TO n - 1
SET key = arr[i]
SET j = i - 1
WHILE j >= 0 AND arr[j] > key
SET arr[j+1] = arr[j]
SET j = j - 1
END WHILE
SET arr[j+1] = key
END FOR
END InsertionSort
SET n = LENGTH(arr)
FOR i FROM 1 TO n - 1
SET key = arr[i]
SET j = i - 1
WHILE j >= 0 AND arr[j] > key
SET arr[j+1] = arr[j]
SET j = j - 1
END WHILE
SET arr[j+1] = key
END FOR
END InsertionSort
6. Merge Sort
BEGIN MergeSort(arr, left, right)
IF left < right THEN
SET mid = (left + right) / 2
CALL MergeSort(arr, left, mid)
CALL MergeSort(arr, mid+1, right)
CALL Merge(arr, left, mid, right)
END IF
END MergeSort
// Implementation of merge function
BEGIN Merge(arr, left, mid, right)
// Merge logic here
END Merge
IF left < right THEN
SET mid = (left + right) / 2
CALL MergeSort(arr, left, mid)
CALL MergeSort(arr, mid+1, right)
CALL Merge(arr, left, mid, right)
END IF
END MergeSort
// Implementation of merge function
BEGIN Merge(arr, left, mid, right)
// Merge logic here
END Merge
7. Quick Sort
BEGIN QuickSort(arr, low, high)
IF low < high THEN
SET pivotIndex = PARTITION(arr, low, high)
CALL QuickSort(arr, low, pivotIndex - 1)
CALL QuickSort(arr, pivotIndex + 1, high)
END IF
END QuickSort
// Implementation of partition function
BEGIN PARTITION(arr, low, high)
// Partition logic here
END PARTITION
IF low < high THEN
SET pivotIndex = PARTITION(arr, low, high)
CALL QuickSort(arr, low, pivotIndex - 1)
CALL QuickSort(arr, pivotIndex + 1, high)
END IF
END QuickSort
// Implementation of partition function
BEGIN PARTITION(arr, low, high)
// Partition logic here
END PARTITION
8. Factorial (Recursive)
BEGIN Factorial(n)
IF n = 0 OR n = 1 THEN
RETURN 1
ELSE
RETURN n * Factorial(n - 1)
END IF
END Factorial
IF n = 0 OR n = 1 THEN
RETURN 1
ELSE
RETURN n * Factorial(n - 1)
END IF
END Factorial
9. Fibonacci Sequence
BEGIN Fibonacci(n)
IF n = 0 THEN
RETURN 0
ELSE IF n = 1 THEN
RETURN 1
ELSE
RETURN Fibonacci(n-1) + Fibonacci(n-2)
END IF
END Fibonacci
IF n = 0 THEN
RETURN 0
ELSE IF n = 1 THEN
RETURN 1
ELSE
RETURN Fibonacci(n-1) + Fibonacci(n-2)
END IF
END Fibonacci
10. Finding Maximum Element
BEGIN FindMax(arr)
SET max = arr[0]
FOR i FROM 1 TO LENGTH(arr) - 1
IF arr[i] > max THEN
SET max = arr[i]
END IF
END FOR
RETURN max
END FindMax
SET max = arr[0]
FOR i FROM 1 TO LENGTH(arr) - 1
IF arr[i] > max THEN
SET max = arr[i]
END IF
END FOR
RETURN max
END FindMax