buggy search adn sort solved
package buggy;
import java.util.Arrays;
/**
* This class looks like it's meant to provide a few public static methods
* for searching and sorting arrays. It also has a main method that tests
* the searching and sorting methods.
*
* TODO: The search and sort methods in this class contain bugs that can
* cause incorrect output or infinite loops. Use the Eclipse debugger to
* find the bugs and fix them
*/
public class BuggySearchAndSort {
public static void main(String[] args) {
int[] A = new int[10]; // Create an array and fill it with random ints.
for (int i = 0; i < 10; i++)
A[i] = 1+ (int)(10 * Math.random());
int[] B = A.clone(); // Make copies of the array.
int[] C = A.clone();
int[] D = A.clone();
System.out.print("The array is:");
printArray(A);
if (contains(A,5))
System.out.println("This array DOES contain 5.");
else
System.out.println("This array DOES NOT contain 5.");
Arrays.sort(A); // sort using Java's built-in sort method!
System.out.print("Sorted by Arrays.sort(): ");
printArray(A);
sweepSort(B);
System.out.print("Sorted by Sweep Sort: ");
printArray(B);
selectionSort(C);
System.out.print("Sorted by Selection Sort: ");
printArray(C);
insertionSort(D);
System.out.print("Sorted by Insertion Sort: ");
printArray(D);
}
/**
* Tests whether an array of ints contains a given value.
* @param array a non-null array that is to be searched
* @param val the value for which the method will search
* @return true if val is one of the items in the array, false if not
*/
//A feww lines were added extra, 'else and 'returnfalse' were added in extra, I have removed those lines
public static boolean contains(int[] array, int val) {
for (int i = 0; i < array.length; i++) {
if (array[i] == val)
return true;
// ERROR 1 was here
}
return false;
}
/**
* Sorts an array into non-decreasing order. This inefficient sorting
* method simply sweeps through the array, exchanging neighboring elements
* that are out of order. The number of times that it does this is equal
* to the length of the array.
*/
//I have commented '***' for the line that contains the error
// i++ was written instead of j++
public static void sweepSort(int[] array) {
for (int i = 0; i < array.length; i++) {
for (int j = 0; j < array.length-1; j++) {// *** ERROR 2 is i++ was written instead of j++
if (array[j] > array[j+1]) { // swap elements j and j+1
int temp = array[j];
array[j] = array[j+1];
array[j+1] = temp;
}
}
}
}
/**
* Sorts an array into non-decreasing order. This method uses a selection
* sort algorithm, in which the largest item is found and placed at the end of
* the list, then the second-largest in the next to last place, and so on.
*/
//I have commented '***' for the line that contains the error
//i + 1 instead of i = 0
// array[1] instead of array[i]
public static void selectionSort(int[] array) {
for (int top = array.length - 1; top > 0; top--) {
int positionOfMax = 0;
for (int i = 0; i <= top; i++) { // *** Error 3 is i + 1 instead of i = 0
if (array[i] > array[positionOfMax]) //*** Error 3 is array[1] instead of array[i]
positionOfMax = i;
}
int temp = array[top]; // swap top item with biggest item
array[top] = array[positionOfMax];
array[positionOfMax] = temp;
}
}
/**
* Sorts an array into non-decreasing order. This method uses a standard
* insertion sort algorithm, in which each element in turn is moved downwards
* past any elements that are greater than it.
*/
//I have commented '***' for the line that contains the error
// > were added instead of >=
//pos was entered instead of pos +1
public static void insertionSort(int[] array) {
for (int top = 1; top < array.length; top++) { // *** ERROR 4 is > were added instead of >=
int temp = array[top]; // copy item that into temp variable
int pos = top - 1;
while (pos >= 0 && array[pos] >= temp) {
// move items that are bigger than temp up one position
array[pos+1] = array[pos];
pos--;
}
array[pos + 1] = temp; // *** ERROR 4 is //pos was entered instead of pos +1
// place temp into last vacated position
}
}
/**
* Outputs the ints in an array on one line, separated by spaces,
* with a line feed at the end.
*/
private static void printArray(int[] array) {
for (int i = 0; i < array.length; i++) {
System.out.print(" ");
System.out.print(array[i]);
}
System.out.println();
}
}
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