1. Module 8 – Searching & Sorting AlgorithmsPs
Module 8 – Searching & Sorting Algorithms
6/9/2019
CSE 1321 Module 8

2. Linear Search Algorithm
METHOD LinearSearch (parameter: list G, target)
BEGIN
FOR each element temp in list G
IF (temp == target)
RETURN true
ENDIF
ENDFOR
RETURN false
END LinearSearch Ps 5
4/26/2018
CSE 1321 Module 8

3. Java Linear Search Algorithm
public boolean linearSearch (int[] array, int target) {
for (int i = 0; i < array.length; i++)
// If we find a match, return true
if (array[i] == target)
return true; }
return false; 6
4/26/2018
CSE 1321 Module 8

4. Binary Search Algorithm
METHOD BinarySearch (parameters: array G, target)
BEGIN
low ← 0, mid ← 0, high ← the number of elements in G
WHILE (true)
mid ← (low + high) / 2
IF (target = G[mid])
RETURN true
ELSE IF (target < G[mid])
high ← mid
ELSE
low ← mid
ENDIF
IF (mid+1 >= high)
RETURN false
ENDWHILE
END BinarySearch Ps
4/26/2018
CSE 1321 Module 8

5. Java Binary Search Algorithm
public static boolean BinarySearch(int[] searchArray, int find) {
boolean found = false;
int low = 0, mid = 0, high = searchArray.length;
while (!found)
mid = (low + high) / 2;
if (find == searchArray[mid])
return true;
else if (find < searchArray[mid])
high = mid;
else
low = mid;
if (low >= high - 1)
return false; }
return found;
4/26/2018
CSE 1321 Module 8

6. Exchange Sort Algorithm
// You should take the time to trace through this
FOR each I from 1 to n
FOR each J from I+1 to n
IF (A[J] < A[I])
temp ← A[J]
A[J] ← A[I]
A[I] ← temp
ENDIF
ENDFOR Ps
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7. Java Exchange Sort Algorithm
for (int i = 0; i < unsorted.length - 1; i++) {
for (int j = i+1; j < unsorted.length; j++)
if (unsorted[j] < unsorted [i])
int temp = unsorted [j];
unsorted [j] = unsorted [i];
unsorted [i] = temp; }
CSE 1321 Module 8 18
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8. Selection Sort Algorithm
FOR each I from 0 to n
minPos ← I
FOR each J from I + 1 to n
IF (B[j] < B[minPos])
minPos ← J
ENDIF
ENDFOR
IF (I != minPos AND minPos < n)
temp ← B[minPos]
B[minPos] ← B[I]
B[I] ← temp Ps
CSE 1321 Module 8 23
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9. Java Selection Sort Algorithm
for (int i = 0; i < B.length - 1; i++) {
int minPos = i;
for (int j = i + 1; j < B.length; j++)
if (B[j] < B[minPos])
minPos = j; }
if (i != minPos && minPos < B.length)
int temp = B[minPos];
B[minPos] = B[i];
B[i] = temp;
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10. Insertion Sort Algorithm
FOR each index from 2 to n
key ← A[index]
position ← index
// Shift larger values to the right
WHILE (position > 0 AND key < A[position-1])
A[position] = A[position - 1]
position ← position -1
ENDWHILE
list [position] = key
ENDFOR Ps
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11. Java Insertion Sort Algorithm
public void insertionSort (int[] list) {
for (int index=1; index < list.length; index++)
int key = list [index];
int position = index;
// Shift larger values to the right
while (position > 0 && key < list[position-1])
list [position] = list [position - 1];
position--; }
list [position] = key;
CSE 1321 Module 8 31
4/26/2018

12. Sorting in a Java Program
The Arrays and ArrayList classes contains sort methods.
To use them, the data type you are sorting must be able to be naturally ordered or you must specify a comparator
The Arrays class belongs to java.util.Arrays.
int [] list1 = new int[10];
ArrayList <Person> errorList= new ArrayList<Person>();
Arrays.sort(list1);
errorList.sort(null);
CSE 1321 Module 8
4/26/2018