Lecture 23: Introduction to 2D Arrays in C++ || LeetCode Questions

In this Video, we are going to learn about 2D Arrays and solve the following questions:
- Row-wise Input/Column wise input
- Linear Search over 2D arrays
- Row-wise Sum/Column wise Sum
- Largest Row sum
- Wave Print
- Spiral Print
- Rotate a Matrix by 90 degrees
- Search in a 2D Matrix I LeetCode
- Search in a 2D Matrix II LeetCode

There is a lot to learn, Keep in mind “ Mnn boot karega k chor yrr apne se nahi yoga ya maza nahi para, Just ask 1 question “ Why I started ? “

Homework: timestamps added below

Question Links:

Do provide you feedback in the comments, we are going to make it best collectively.

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Intro Sequence: We have bought all the required Licenses of the Audio, Video & Animation used.

Timestamps:

00:00 - Introduction
00:50 - Why we need 2-D Arrays ?
03:03 - How 2D stored in memory ?
04:22 - Promotion
05:26 - How 2D stored in memory ?
07:47 - Creating an 2D Array
09:51 - taking input in 2D Array
10:42 - Output in 2D Arrays
12:44 - Coding - Creating, Input & Output 2D Array
14:44 - Row-wise Input ion 2D Arrays
15:12 - Column-wise input in 2D Arrays
18:25 - Initialising 2D Arrays
20:45 - Linear Search in 2D Arrays
25:15 - Row-wise Sum Problem
32:22 - Largest Row Sum Problem
37:24 - Wave Print Problem
39:00 - Approach
41:00 - Code
45:22 - Time Complexity of Solution
46:20 - Spiral Print Problem
47:33 - Approach
50:45 - Code
59:17 - Time Complexity of Solution
01:00:35 - Homework
01:01:44 - Binary Search on 2D Arrays
01:02:44 - Search a 2D Matrix LeetCode Level1 Problem
01:03:55 - Approach
01:07:08 - Code
01:16:45 - Time Complexity of Solution
01:17:30 - Search a 2D Matrix LeetCode Level2 Problem
01:18:17 - Approach
01:23:29 - Code
01:28:10 - How to approach a problem ?

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[pratham]

Till now I am able to solve leet code easy and some medium problems based on binary search and sorting of arrays. It is because of your course. Thank you so much...

[suranjandhara]

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Love you from West Bengal, Hooghly

[aayushkhurana]

There are some other good courses of this level on YouTube but your way of teaching it making everything easy for students to understand makes it Class apart from others.

[mdwaqar]

It took me 3 Days to Digest all the Solutions again but now I am Confident and can code similar types of Questions. Thanks So much. Onto the Next video.

[CHANDANKUMAL-dbbp]

22:53 When passing a two-dimensional array to a function, you must specify the number of columns as a constant when you write the parameter type, so the compiler can pre-calculate the memory addresses of individual elements.

[krish]

i was about to give up on this playlist .. but got the approach of binary search on 2d couple of minutes before your solution and now i am again boosted with confidence ..

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[prateekkosta]

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[vigneshv]

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[aiwithsaqi]

Rotate array solution
Approach: simply transpose the matrix and then reverse that matrix
Note: Transpose: change rows into column and column into rows.
time complexity : O(N^2)

class Solution {
public:
void rotate(vector<vector<int>>& matrix) {

//tranaspose
for(int i =0; i<matrix.size();i++){
for(int j =0 ; j<i ; j++){
swap(matrix[i][j], matrix[j][i]);
}
}
//reverse
for(int i=0;i<matrix.size();i++){

reverse(matrix[i].begin(), matrix[i].end());
}

}
};

[JGyanRaj]

Amazing teaching method. 2D arrays ke nam se dar lagta tha... Or upar se binary search aa jaye to behosh ho jate the but now everything seems to be peace of cake. All credit goes to Babbar Bhaiya.

Happy New year Bhaiya Ji 🙏.

[AbhiRajSingh]

Watching this series again, thanks for making this masterpiece. 🙂

[vallabhshelar]

1:01:00 the 90 degree rotation column can be easily solved by making the columns the rows. It means taking the transpose of a matrix

[techyouknow]

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[ashishashish]

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[Nikhil-xdo]

Bhaiya Ji sach me aapke padhaye hue playlist ki charcha har college me ho rahi lekin bhaiya ji sach bole toh abhi tak dhang se soach nahi pa rahe pryaas jari rahega )

[lakshayyadav]

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[copilotcoder]

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[raisanjeeb]

Thank You bhaiya....Lga jaise khud pdh rha hu aur sab samajh aa rha ...Thank You bhaiya✨✨👑