Saturday, July 26, 2025

📅 Day 2 Plan – Core Concepts & Application SSC CGL

 ⏱️ Total Study Time: 6–8 hours

SubjectTopic
🧠 ReasoningAlphabet Series + Coding-Decoding
📐 QuantHCF, LCM Tricks + Application
📖 EnglishSynonyms/Antonyms + Sentence Correction
🌏 GKFundamental Rights + Static GK

🧠 1. Reasoning – Alphabet Series + Coding-Decoding

Alphabet Series

  • A=1, B=2, ..., Z=26

  • Understand forward & backward movement

  • Practice patterns like:

    • A, C, E, G, ?, ?

    • Z, X, V, T, ?

Coding-Decoding Basics

  • Example:
    If CAT = DBU, then code logic is +1 for each letter.
    So, DOG = ?EPH


🎯 Practice Now:

  1. A, C, F, J, O, ?

  2. If TABLE = UBCMF, then CHAIR = ?

  3. If MANGO = NZOHQ, what is the code for GRAPE?

📌 Try and send your answers — I’ll explain them.


📐 2. Quant – HCF & LCM

✅ Concepts:

  • HCF: Highest number that divides both

  • LCM: Smallest common multiple

  • Formula:
    HCF × LCM = Product of two numbers


🎯 Practice:

  1. HCF of 60 and 48?

  2. LCM of 15, 20?

  3. If HCF = 6 and LCM = 120, what are possible numbers?

  4. Two numbers have HCF = 12 and LCM = 180. If one number is 36, find the other.

📌 Solve & reply — we’ll do step-by-step correction.


📖 3. English – Synonyms & Error Spotting

✅ 10 Important Synonyms (Learn these):

  1. Rapid – Fast

  2. Generous – Kind

  3. Ancient – Old

  4. Brave – Courageous

  5. Enormous – Huge

  6. Genuine – Real

  7. Polite – Courteous

  8. Silent – Mute

  9. Answer – Reply

  10. Famous – Renowned

📝 Task: Write sentences using 5 of them!


✅ Grammar Practice (Fix errors):

  1. He don’t goes to gym daily.

  2. Neither of the boy are present.

  3. She is knowing the truth.

📌 Reply with corrected versions — I’ll guide.


🌏 4. GK – Indian Constitution: Fundamental Rights

🇮🇳 6 Fundamental Rights:

  1. Right to Equality

  2. Right to Freedom

  3. Right against Exploitation

  4. Right to Freedom of Religion

  5. Cultural and Educational Rights

  6. Right to Constitutional Remedies

Q&A:

  • Who is called the “Father of Indian Constitution”?

  • How many articles are there in the Indian Constitution?

  • Which Article gives Right to Education?


📰 Current Affairs Task:

👉 Read top 5 headlines of June 27 & 28 from GKToday
📌 You can ask me for a summary too!


Homework Summary for Day 2

SubjectTask
Reasoning3 coding/series questions
Quant4 HCF/LCM questions
EnglishLearn synonyms + fix 3 sentences
GKLearn 6 rights + 3 polity questions
CARead today’s current affairs

📘 DAY 1 (1-50): FOUNDATION - SSC CGL

 

📘 DAY 1: FOUNDATION

We’ll cover today:

  1. Reasoning – Number Series

  2. Quant – Number System Basics

  3. English – Vocabulary & Error Spotting

  4. GK – Indian Polity + Current Affairs


🧠 1. Reasoning – Number Series

🔍 Concept:

A number series is a sequence that follows a logical rule. Your task is to find the next number or find the wrong one.

🧩 Example Patterns:

  • Addition: 2, 4, 6, 8, __ (Answer: 10)

  • Multiplication: 3, 6, 12, 24, __ (Answer: 48)

  • Squares: 1, 4, 9, 16, __ (Answer: 25)

  • Fibonacci: 1, 1, 2, 3, 5, 8, __ (Answer: 13)


🎯 Practice Now (Try these):

  1. 2, 6, 12, 20, 30, ?

  2. 5, 10, 20, 40, ?

  3. 100, 81, 64, 49, ?

  4. 1, 4, 9, 16, 25, ?

📌 Write answers and reply — I’ll check and explain.


📐 2. Quant – Number System Basics

✍️ Concepts:

  • Types of Numbers:

    • Natural: 1, 2, 3...

    • Whole: 0, 1, 2...

    • Even: 2, 4, 6...

    • Prime: 2, 3, 5, 7...

  • Divisibility Rules (Learn today for 2 to 6)

    • Div by 2: Ends in 0, 2, 4, 6, 8

    • Div by 3: Sum of digits divisible by 3

    • Div by 5: Ends in 0 or 5

    • Div by 6: Divisible by 2 and 3 both


🎯 Practice Now:

  1. Find LCM of 18 and 24

  2. Is 527 divisible by 3?

  3. Which is the smallest number divisible by 6, 8 and 12?

  4. What type of number is 1? (Prime/Composite?)

📌 Write your answers — I’ll review and teach more if needed.


📖 3. English – Vocab + Grammar

📝 Task:

  • Learn these 10 words:

    • Abandon

    • Benevolent

    • Candid

    • Deter

    • Elusive

    • Frugal

    • Hinder

    • Jubilant

    • Keen

    • Lucid

Write 2 sentences for each to learn better!


🧐 Grammar Practice:

Find the error:

  1. She go to school everyday.

  2. He don’t like tea.

  3. They has gone to the market.

📌 Try fixing these. I’ll explain each.


🌏 4. GK – Indian Polity (Basics)

🇮🇳 Learn Today:

  • First President of India – Dr. Rajendra Prasad

  • Current President (2025) – You tell me?

  • Rajya Sabha – Upper House

  • Lok Sabha – Lower House

  • Members in Lok Sabha – 543

  • Members in Rajya Sabha – 245


📰 Current Affairs (June 2025):

👉 Visit AffairsCloud or GKToday and read:

  • National events

  • Sports

  • Government schemes launched in June

📌 I can send today’s curated current affairs summary too, just say yes.


✅ Homework Summary

SubjectTask
ReasoningSolve 5 number series
QuantPractice 4 number system questions
EnglishLearn 10 words + correct 3 sentences
GKRevise polity + read June 2025 current affairs

✅ Topics for Day 6 DSA with Java

Focus: Two Pointer Technique


🔁 1. Learn & Implement Two Pointer Technique

  • Understand how the two-pointer technique works on sorted arrays.

  • Implement the following problems:


// Java Example: Two Sum (Sorted Array) public int[] twoSum(int[] numbers, int target) { int left = 0, right = numbers.length - 1; while (left < right) { int sum = numbers[left] + numbers[right]; if (sum == target) { return new int[] { left + 1, right + 1 }; // 1-indexed } else if (sum < target) { left++; } else { right--; } } return new int[] {}; // no solution }

🧠 2. Solve 2 LeetCode Problems Using Two Pointers

  1. LeetCode 167. Two Sum II – Input Array Is Sorted

  2. LeetCode 283. Move Zeroes


✨ Bonus Challenges (Optional but Recommended)


📊 Explore Visualization

Try two-pointer visualizations at:
👉 https://visualgo.net/en/list


🧩 Concept Summary

Friday, July 4, 2025

✅ Day 5 Solution - DSA with Java

 

✅ 1. Implement Merge Sort and Quick Sort

🔹 Merge Sort


public class MergeSort { public static void mergeSort(int[] arr, int left, int right) { if (left < right) { int mid = (left + right) / 2; mergeSort(arr, left, mid); mergeSort(arr, mid + 1, right); merge(arr, left, mid, right); } } public static void merge(int[] arr, int left, int mid, int right) { int n1 = mid - left + 1, n2 = right - mid; int[] L = new int[n1]; int[] R = new int[n2]; for (int i = 0; i < n1; i++) L[i] = arr[left + i]; for (int j = 0; j < n2; j++) R[j] = arr[mid + 1 + j]; int i = 0, j = 0, k = left; while (i < n1 && j < n2) { if (L[i] <= R[j]) arr[k++] = L[i++]; else arr[k++] = R[j++]; } while (i < n1) arr[k++] = L[i++]; while (j < n2) arr[k++] = R[j++]; } }

🔹 Quick Sort


public class QuickSort { public static void quickSort(int[] arr, int low, int high) { if (low < high) { int pi = partition(arr, low, high); quickSort(arr, low, pi - 1); quickSort(arr, pi + 1, high); } } public static int partition(int[] arr, int low, int high) { int pivot = arr[high]; int i = low - 1; for (int j = low; j < high; j++) { if (arr[j] < pivot) { i++; // Swap int temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } } // Final pivot swap int temp = arr[i + 1]; arr[i + 1] = arr[high]; arr[high] = temp; return i + 1; } }

✅ 2. LeetCode Problems


🔸 Merge Sorted Array

Merge nums2 into nums1 sorted in-place.


public class MergeSortedArray { public static void merge(int[] nums1, int m, int[] nums2, int n) { int i = m - 1, j = n - 1, k = m + n - 1; while (i >= 0 && j >= 0) { nums1[k--] = (nums1[i] > nums2[j]) ? nums1[i--] : nums2[j--]; } while (j >= 0) { nums1[k--] = nums2[j--]; } } }

🔸 Sort an Array

Use any sorting method. Here's Merge Sort used:


public class SortAnArray { public static int[] sortArray(int[] nums) { mergeSort(nums, 0, nums.length - 1); return nums; } public static void mergeSort(int[] arr, int l, int r) { if (l < r) { int m = (l + r) / 2; mergeSort(arr, l, m); mergeSort(arr, m + 1, r); merge(arr, l, m, r); } } public static void merge(int[] arr, int l, int m, int r) { int n1 = m - l + 1, n2 = r - m; int[] L = new int[n1]; int[] R = new int[n2]; for (int i = 0; i < n1; ++i) L[i] = arr[l + i]; for (int j = 0; j < n2; ++j) R[j] = arr[m + 1 + j]; int i = 0, j = 0, k = l; while (i < n1 && j < n2) arr[k++] = (L[i] <= R[j]) ? L[i++] : R[j++]; while (i < n1) arr[k++] = L[i++]; while (j < n2) arr[k++] = R[j++]; } }

✅ 3. Non-Recursive Quick Sort (Iterative)


import java.util.Stack; public class QuickSortIterative { public static void quickSort(int[] arr) { Stack<int[]> stack = new Stack<>(); stack.push(new int[]{0, arr.length - 1}); while (!stack.isEmpty()) { int[] range = stack.pop(); int low = range[0], high = range[1]; if (low < high) { int pi = partition(arr, low, high); stack.push(new int[]{low, pi - 1}); stack.push(new int[]{pi + 1, high}); } } } private static int partition(int[] arr, int low, int high) { int pivot = arr[high], i = low - 1; for (int j = low; j < high; j++) { if (arr[j] < pivot) { i++; // Swap int temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } } // Final pivot placement int temp = arr[i + 1]; arr[i + 1] = arr[high]; arr[high] = temp; return i + 1; } }

✅ 4. Visualize Merge vs Quick Sort

You can interactively visualize how Merge and Quick Sort work at:

🔗 Visualgo.net – Sorting Visualizations

Click:

  • Merge Sort → observe divide → merge steps

  • Quick Sort → watch pivot partitioning → recursive reduction

💡 Use small array sizes (e.g. 10 elements) to step-through for learning.

🚀 Day 5: Merge Sort & Quick Sort in Java 🎯 Goals for Today


  • Understand the Divide and Conquer strategy

  • Learn and implement:

    • Merge Sort

    • Quick Sort

  • Analyze Time & Space Complexities

  • Solve intermediate-level sorting problems


📘 1. Merge Sort

A stable, divide-and-conquer sorting algorithm.
Time Complexity: O(n log n) in all cases
Space Complexity: O(n) (extra array)

✅ Logic:

  • Divide the array into two halves

  • Sort each half recursively

  • Merge the two sorted halves

🔹 Java Implementation


public class MergeSort { public static void mergeSort(int[] arr, int left, int right) { if (left < right) { int mid = (left + right) / 2; // Sort the left and right halves mergeSort(arr, left, mid); mergeSort(arr, mid + 1, right); // Merge them merge(arr, left, mid, right); } } public static void merge(int[] arr, int left, int mid, int right) { int n1 = mid - left + 1; int n2 = right - mid; int[] L = new int[n1]; int[] R = new int[n2]; for (int i = 0; i < n1; i++) L[i] = arr[left + i]; for (int j = 0; j < n2; j++) R[j] = arr[mid + 1 + j]; int i = 0, j = 0, k = left; while (i < n1 && j < n2) { if (L[i] <= R[j]) arr[k++] = L[i++]; else arr[k++] = R[j++]; } while (i < n1) arr[k++] = L[i++]; while (j < n2) arr[k++] = R[j++]; } }

⚡ 2. Quick Sort

Quick and efficient, especially on average cases.
Time Complexity:

  • Best/Average: O(n log n)

  • Worst: O(n²) (when pivot is worst chosen)
    Space: O(log n) (due to recursive calls)

✅ Logic:

  • Choose a pivot

  • Partition the array: elements < pivot go left, > pivot go right

  • Recursively sort left and right

🔹 Java Implementation


public class QuickSort { public static void quickSort(int[] arr, int low, int high) { if (low < high) { int pi = partition(arr, low, high); quickSort(arr, low, pi - 1); quickSort(arr, pi + 1, high); } } public static int partition(int[] arr, int low, int high) { int pivot = arr[high]; int i = low - 1; // Index of smaller element for (int j = low; j < high; j++) { if (arr[j] < pivot) { i++; // Swap int temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } } // Swap pivot to the right place int temp = arr[i + 1]; arr[i + 1] = arr[high]; arr[high] = temp; return i + 1; } }

📊 3. Merge Sort vs Quick Sort

FeatureMerge SortQuick Sort
Time (Best)O(n log n)O(n log n)
Time (Worst)O(n log n)O(n²)
SpaceO(n)O(log n)
Stable✅ Yes❌ No
In-place❌ No✅ Yes
Use CaseLinked listsArrays

🧠 4. Practice Problems

Try these problems:

  1. Merge Sorted Array

  2. Sort an Array

  3. 🔁 Kth Largest Element in Array – Use Quick Select

  4. 🧠 Count Inversions in Array – Use Merge Sort logic


📚 Homework for Day 5

  • Implement Merge Sort and Quick Sort

  • Solve 2 LeetCode problems involving sorting or partitioning

  • Try to write non-recursive quick sort (advanced)

  • Visualize Merge vs Quick: Try https://visualgo.net/en/sorting


🔜 Coming Up on Day 6:

  • Recursion Mastery

  • Backtracking intro (Subset, Permutations)

  • Understanding call stack and dry runs

✅ Day 4 Solution - DSA with Java

 

✅ 1. Implement All Three Sorting Algorithms

🔹 Bubble Sort


public class BubbleSort { public static void bubbleSort(int[] arr) { int n = arr.length; for (int i = 0; i < n - 1; i++) { boolean swapped = false; for (int j = 0; j < n - i - 1; j++) { if (arr[j] > arr[j + 1]) { // Swap int temp = arr[j]; arr[j] = arr[j + 1]; arr[j + 1] = temp; swapped = true; } } if (!swapped) break; // Optimization } } }

🔹 Selection Sort


public class SelectionSort { public static void selectionSort(int[] arr) { int n = arr.length; for (int i = 0; i < n - 1; i++) { int minIdx = i; for (int j = i + 1; j < n; j++) { if (arr[j] < arr[minIdx]) { minIdx = j; } } // Swap int temp = arr[i]; arr[i] = arr[minIdx]; arr[minIdx] = temp; } } }

🔹 Insertion Sort


public class InsertionSort { public static void insertionSort(int[] arr) { for (int i = 1; i < arr.length; i++) { int key = arr[i]; int j = i - 1; while (j >= 0 && arr[j] > key) { arr[j + 1] = arr[j]; j--; } arr[j + 1] = key; } } }

✅ 2. LeetCode Problems


🔸 Problem 1: Sort Colors

Sort an array containing only 0s, 1s, and 2s.
Use Dutch National Flag Algorithm (O(n) time, O(1) space)


public class SortColors { public static void sortColors(int[] nums) { int low = 0, mid = 0, high = nums.length - 1; while (mid <= high) { if (nums[mid] == 0) { // Swap with low int temp = nums[low]; nums[low] = nums[mid]; nums[mid] = temp; low++; mid++; } else if (nums[mid] == 1) { mid++; } else { // nums[mid] == 2 int temp = nums[mid]; nums[mid] = nums[high]; nums[high] = temp; high--; } } } }

🔸 Problem 2: Check if Array Is Sorted and Rotated

Return true if array is sorted and rotated at most once.

🔍 Logic:

Count how many times arr[i] > arr[i+1]. If it happens more than once, it's not valid.


public class CheckSortedRotated { public static boolean check(int[] nums) { int count = 0; int n = nums.length; for (int i = 0; i < n; i++) { if (nums[i] > nums[(i + 1) % n]) { count++; } } return count <= 1; } public static void main(String[] args) { int[] arr = {3, 4, 5, 1, 2}; System.out.println("Is Sorted and Rotated? " + check(arr)); // true } }

🧠 Summary of Day 4

  • ✅ Bubble, Selection, Insertion Sort implemented

  • ✅ LeetCode problems solved

    • Dutch National Flag (0s, 1s, 2s)

    • Check Sorted & Rotated

✅ Day 5 Solution - DSA with C

 

✅ 1. Implement your own strlen()


#include <stdio.h> int my_strlen(char str[]) { int i = 0; while (str[i] != '\0') { i++; } return i; } int main() { char str[100]; printf("Enter a string: "); scanf("%s", str); printf("Length of string = %d\n", my_strlen(str)); return 0; }

✅ 2. Implement your own strcpy()


#include <stdio.h> void my_strcpy(char dest[], char src[]) { int i = 0; while (src[i] != '\0') { dest[i] = src[i]; i++; } dest[i] = '\0'; // Null-terminate } int main() { char src[100], dest[100]; printf("Enter a string to copy: "); scanf("%s", src); my_strcpy(dest, src); printf("Copied string: %s\n", dest); return 0; }

✅ 3. Implement your own strcmp()


#include <stdio.h> int my_strcmp(char str1[], char str2[]) { int i = 0; while (str1[i] != '\0' && str2[i] != '\0') { if (str1[i] != str2[i]) return str1[i] - str2[i]; i++; } return str1[i] - str2[i]; // Also handles different lengths } int main() { char str1[100], str2[100]; printf("Enter two strings:\n"); scanf("%s %s", str1, str2); int result = my_strcmp(str1, str2); if (result == 0) printf("Strings are equal.\n"); else if (result < 0) printf("First string is smaller.\n"); else printf("First string is greater.\n"); return 0; }

✅ 4. LeetCode Problem: Valid Anagram

Two strings are anagrams if they contain the same characters in any order.

✨ Custom C Solution:


#include <stdio.h> #include <string.h> int isAnagram(char s[], char t[]) { int count[26] = {0}; if (strlen(s) != strlen(t)) return 0; for (int i = 0; s[i] != '\0'; i++) { count[s[i] - 'a']++; count[t[i] - 'a']--; } for (int i = 0; i < 26; i++) { if (count[i] != 0) return 0; } return 1; } int main() { char s[100], t[100]; printf("Enter first string: "); scanf("%s", s); printf("Enter second string: "); scanf("%s", t); if (isAnagram(s, t)) printf("Valid Anagram\n"); else printf("Not an Anagram\n"); return 0; }

✅ This C code solves the Valid Anagram LeetCode problem without using libraries like sort.

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