π Revision Dashboard
Spaced repetition system to reinforce your learning
π How Revision Works
β’ Day 2 (1 day elapsed): Revise the problem solved yesterday (Daily Review)
β’ Day 3 (2 days elapsed): Revise the problem solved 2 days ago (Second Daily Review)
β’ Day 8 (7 days elapsed): Revise all problems from that week (Weekly Review)
β’ Day 31 (30 days elapsed): Revise all problems from that month (Monthly Review)
β°Due Today (40)
Single Number
LeetCode
import sys
from typing import List
from functools import reduce...Power of Two
LeetCode
import sys
class Solution:
# Optimized: O(1) Time, O(1) Space - Bitwise Trick...Permutations (Backtracking)
LeetCode
import sys
from typing import List
class Solution:Subsets (Backtracking)
LeetCode
import sys
from typing import List
class Solution:Check Palindrome and Armstrong Number
TakeUForward
import sys
# O(log N) Time, O(1) Space - Optimal
def is_palindrome_optimal(n: int) -> bool:...Greatest Common Divisor (GCD/HCF)
TakeUForward
import sys
# Optimal: O(log(min(A,B))) Time - Euclidean Algorithm (Recursive)
def gcd_recursive(a, b):...Count Digits and Reverse Number
TakeUForward
import sys
def solve_digit_manipulation():
try:...Spiral Traversal of Matrix
Smart Interviews
import sys
def spiralTraversal_optimal(matrix):
"""O(N^2) Time, O(1) Space - Boundary Pointers"""...Diagonal Traversal of Matrix
Smart Interviews
import sys
from collections import defaultdict
def diagonalTraversal_optimal(matrix):...Rotation of Matrix (90 Degrees Clockwise)
Smart Interviews
import sys
def rotateMatrix_optimal(matrix):
"""O(N^2) Time, O(1) Space - Transpose then Reverse"""...Valid Parentheses
LeetCode
import sys
class Solution:
# Optimized: O(N) Time, O(N) Space - Stack and Hash Map (Dictionary)...Integer to Roman
LeetCode
import sys
class Solution:
# Use paired lists or a tuple of tuples for the lookup table, ordered largest to smallest...First Unique Character in a String
LeetCode
import sys
from collections import Counter
class Solution:...Roman to Integer
LeetCode
import sys
class Solution:
# O(N) Time, O(1) Space - Right-to-Left Traversal (Cleanest Optimal)...Valid Palindrome (Alpha-Numeric Filter)
LeetCode
import sys
def solve_valid_palindrome():
try:Reverse Words in a String
LeetCode
import sys
def solve_reverse_words():
try:Compress String (Run-Length Encoding)
Smart Interviews
import sys
def solve_compress_string():
try:Vowels and Consonants
Smart Interviews
import sys
def solve_vowels_consonants():
try:Letter Coverage (Pangram Check)
Smart Interviews
import sys
def solve_letter_coverage():
try:Digit String Check
Smart Interviews
import sys
def solve_digit_string():
try:Odd Even Index
Smart Interviews
import java.util.Scanner;
class Solution {
public static void solve_odd_even_index() {...Triangle and Pyramid Patterns
Custom
Half Diamond Pattern
Custom
#include <iostream>
using namespace std;
void solve_half_diamond() {...Filled and Hollow Rectangle
Custom
Submatrix Sum
Custom/Smart Interviews
import sys
def solve_submatrix_sum():
# Read NLower Triangle Sum
Smart Interviews
import sys
def solve_lower_triangle_sum():
# Read N...Matrix Row and Column Sums
Smart Interviews
import sys
def solve_matrix_sums():
# Set up fast input reading...Natural Numbers Sum
Smart Interviews
import java.util.Scanner;
class Solution {
public static long sumNaturalNumbers_optimal(long N) {...Factorial
Smart Interviews
#include <iostream>
using namespace std;
long long calculateFactorial_iterative(int N) {...Arithmetic Progression Check
Smart Interviews
import java.util.Scanner;
class Solution {
public static boolean isArithmeticProgression(int[] nums) {...Arithmetic Operators
Smart Interviews
import java.util.Scanner;
class Solution {
public static void performOperation(int A, int B, char op) {...Triangle Validator
Smart Interviews
import java.util.Scanner;
import java.util.Arrays;
class Solution {...Number Distribution (Frequency Count)
Smart Interviews
import java.util.Scanner;
import java.util.Map;
import java.util.TreeMap; ...Find Duplicate Number in Array
Smart Interviews
import java.util.Scanner;
class Solution {
public static int findDuplicate_optimal(int[] nums) {...Odd and Even Sum
Custom
import java.util.Scanner;
class Solution {
public static void calculateOddEvenSum_optimal(int N, Scanner scanner) {...The Missing Number
Custom
import java.util.Scanner;
class Solution {
public static long findMissingNumber_summation(int[] nums) {...Max Element in Array
Smart Interviews
import sys
def solve_max_element():
try:Sparse Arrays
HackerRank
from collections import Counter
from typing import List
# --- Optimized Approach ---...Duplicate Integer
NeetCode 150
from typing import List
class Solution:
# 1. Brute Force Approach: Time O(n^2), Space O(1)...Two Sum
LeetCode
from typing import List
class Solution:
# 1. Optimized Approach: Time O(n), Space O(n) - Dictionary/Hash Map...π‘ Revision Tips
- β’ Try to solve from memory before checking your solution
- β’ Focus on the approach and pattern, not just memorizing code
- β’ Write down what you struggled with for next revision
- β’ If you solved it easily, you've mastered it!