All Flashcards
How is recursion applied in real-world scenarios?
In algorithms like tree traversal, graph searching, and in compilers for parsing code.
How is binary search applied in real-world scenarios?
Searching for a word in a dictionary, finding a contact in a sorted list, or locating data in a sorted database index.
How is merge sort applied in real-world scenarios?
Used in external sorting (sorting large datasets that don't fit in memory), and as a building block in other algorithms.
What does the following code output?
java
public int factorial(int n) {
if (n == 0) {
return 1;
} else {
return n * factorial(n-1);
}
}
System.out.println(factorial(4));
24
Identify the error in the following code:
java
public int factorial(int n) {
return n * factorial(n-1);
}
Missing base case, which will cause a stack overflow error.
What does the following code output?
java
public void traverseArray(int[] array, int index) {
if (index == array.length) {
return;
}
System.out.println(array[index]);
traverseArray(array, index + 1);
}
int[] arr = {1, 2, 3};
traverseArray(arr, 0);
1 2 3
What does the following code output?
java
public int binarySearch(int[] array, int target, int low, int high) {
if (low > high) {
return -1;
}
int mid = (low + high) / 2;
if (array[mid] == target) {
return mid;
} else if (target < array[mid]) {
return binarySearch(array, target, low, mid - 1);
} else {
return binarySearch(array, target, mid + 1, high);
}
}
int[] arr = {2, 4, 6, 8, 10};
System.out.println(binarySearch(arr, 6, 0, arr.length - 1));
2
Identify the potential issue in the following binary search code:
java
int mid = (low + high) / 2;
Integer overflow can occur if low + high exceeds the maximum integer value. Using mid = low + (high - low) / 2; is a safer alternative.
Predict the output of the following code:
java
public int mystery(int n) {
if (n <= 0) {
return 0;
} else {
return n + mystery(n - 2);
}
}
System.out.println(mystery(5));
9
What is the output of the following code?
java
public int recursiveMethod(int num) {
if (num == 0)
return 1;
else
return num * recursiveMethod(num - 1);
}
System.out.println(recursiveMethod(3));
6
What is the output of the following code?
java
public int method(int num) {
if (num == 5)
return 5;
else
return num + method(num + 1);
}
System.out.println(method(2));
14
What is the output of the following code?
java
public int method(int num) {
if (num == 0)
return 0;
else
return 1 + method(num / 2);
}
System.out.println(method(8));
4
What is the output of the following code?
java
public int method(int num) {
if (num == 0)
return 0;
else
return 1 + method(num - 1);
}
System.out.println(method(4));
4
What are the general steps for writing a recursive function?
- Identify the base case(s). 2. Define the recursive call to solve a smaller subproblem. 3. Ensure the recursive call moves towards the base case.
What are the steps of the binary search algorithm?
- Find the middle element. 2. Compare the target to the middle element. 3. If target equals middle, return index. 4. If target is less than middle, search the left half. 5. If target is greater than middle, search the right half. 6. Repeat until found or search space is empty.
What are the main steps of the merge sort algorithm?
- Divide the array into two halves. 2. Recursively sort the two halves. 3. Merge the sorted halves.