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int numIslands(vector<vector<char>>& grid) { int n = grid.size(); int m = grid[0].size(); int dire[4][2]={{1,0},{0,1},{-1,0},{0,-1}}; queue<pair<int,int>>q; int count=0; for(int row = 0;row<n;row++) { for(int col = 0;col<m;col++) { if(grid[row][col]=='1') { count++; q.push({row,col}); grid[row][col]='2'; } while(!q.empty()) { auto x = q.front(); q.pop(); for(auto i : dire) { int r=i[0]+x.first; int c=i[1]+x.second; if(r>=0 && r<n && c>=0 && c<m && grid[r][c]=='1') { q.push({r,c}); grid[r][c]='2'; } } } } } return count; } c++ solution

Thanks sir!!!!

what will happen if last element is duplicate element

Kindly speak louder.

you are awesome finally i understood after looking at 10 videos thank you

Nice 🙂👍

What if the problem states that at most we can delete 2 characters and the deletion should happen from left to right. For example, s = "abjchba". Now to make it palindrome, we can either delete "jc" or "ch". But as per problem, we should be deleting "jc" and correct palindrome would be "abhba". We have to return the characters that we deleted.

Why didnt you run the code ;(

class Main {public static void main(String[] args) { int a [] = {1,2,2,3,4,3,4,5}; Set<Integer> var1=new HashSet<>(); for(int i: a) { var1.add(i); } System.out.println(var1); } }

Nice explanation sir

why is my code aint working class Solution { public int romanToInt(String s) { Map <Character , Integer> map = new HashMap<>(); map.put('I',1); map.put('V',5); map.put('X',10); map.put('L',50); map.put('C',100); map.put('D',500); map.put('M',1000); int result = 0; for (int i=0 ; i<s.length()-1; i++){ if (map.get(s.charAt(i)) >= map.get(s.charAt(i+1))){ result = (map.get(s.charAt(i)) + map.get(s.charAt(i+1))); } else if (map.get(s.charAt(i)) <= map.get(s.charAt(i+1))){ result = (map.get(s.charAt(i+1)) - map.get(s.charAt(i))); } } return result ; } }

why to traverse till s.lenghth()-1 ; we can directly traverse till end of lenght

Instead of a temp array use ArrayList you won't get zeros. public static void main(String[] args) { int a[] = { 1, 1, 2, 2, 3, 3, 4, 5, 6 }; int len = a.length; int j = 0; ArrayList<Integer> arr = new ArrayList<Integer>(); for (int i = 0; i < len - 1; i++) { if (a[i] != a[i + 1]) { arr.add(j++, a[i]); } } arr.add(j++, a[len - 1]); for (int i : arr) { System.out.print(i + " "); } }

Tq

Sir the output is in ordered one..not in unordered one sir

ur voice is too low

Thanks, now I got a clear picture.

Great explanation

Thank you

awesome explanation, need program for : Write a java program for getting the sum of 30 by adding min 3 numbers from count[]={1, 15, 10, 5}. pleas help

Very nicely done

Thanks

Whoever is getting error just put this code at line no. 75 while(k>0){ st.pop(); k--; }

i m not getting how to return collections

plese tell how to return collections from method

int j = 0; for (int i = 0; i < arr.length; i++) { if (arr[i] != 0) { if (i != j) { int temp = arr[i]; arr[i] = arr[j]; arr[j] = temp; } j++; } }

What if in 2nd 60s position there is 65. Does it fail ?. According to algorithm it is coming as 1 while its answer should be 2.

thanks bro!!

public double myPow(double x, int n) { double res = pow(x, Math.abs(n)); if(n<0) return 1/res; return res; } double pow(double x, int n){ if(n==0) return 1; double temp = pow(x, n/2); if(n%2==0) return temp*temp; else { return temp*temp*x; } }

Thank you!!

good sir

Great work. Thank you!!

🙌🙌🙌

you are good teacher and u selected good problems and not the fancy problems

brother you stammer too much.. please speak calmly..it make the understanding better..

Thanks❤

Thanks for this wonderful explanation sir

Best video 🎉

very good video but why we use binarysearchhelper method can you explain me ?

What if you have repeating pairs how would you code it ?

you don't need if equal test, just use else which is the only case left

Simple & great explanation sir compared to others...

tqq sir

Good explanation. I just subscribed

❤

Can you help me with this? I gave 453 as the number in o/p Each time it is saying The digit count in the given number is:1 The digit count in the given number is:2 The digit count in the given number is:3 it is not coming in single line as The digit count in the given number is:3 My program: import java.util.Scanner; public class digits{ public static void main(String args[]){ System.out.print("Enter the number: "); Scanner scan=new Scanner(System.in); int num=scan.nextInt(); int digit_count=0; while(num>0){ num=num/10; digit_count++; System.out.println("The digit count in the given number is: "+digit_count); } } }

HI I need this probem fixed in java 8 .Could you please help me for this probem Given array : 1,3,5,7,9,11,16,20 Input value : 16 Output [2,5][3,4] Write the logic to identify the pairs of index in given array which value sum equal to input value.I have pasted here the problem statement I need solution by using java 8 concepts.

Sir why in my program the count of array elements start from 1, why not 0??

Literally the best explanation thank you sir !

Thank you