Fibonnaci O(LOGN)  

I don't know why I haven't discovered this channel yet... You're a gem.

thanks for making matrix exponentiation very easy 🔥🔥

Saw many videos on matrix exponentiation but this was the best... 🔥🔥

Thanks di ,I was struggling here from a long time..Ur explaination was legit..Cleared the concept 🤩🤩

you are a magician

Great, thank you FIBONACHI MAMA MIA

Best Time Complexity | Iterative | log(n) #define m 1000000007 vector matMul(vector &a, vector &b) { vector ans = {{0, 0}, {0, 0}}; for(int i=0; i

Thanks a log dii❤

I luv u alisha❤

Great 👍

Amazing

great

Great explanation!

Super explain

thank you so much!

good explanation😉

Can anyone explain this line vectorans(2,vector(2,0));

Base case n==-1 can be removed i think beco'z base case 0 is written first

Thank u akka

@harsh-govind I have written the same solution in java but got the wrong result. For instance, n =4 got result as 9. Please correct the solution. public class SumOfNFibonnaci { public int[][] sum(int[][] mat, int nNumber) { if(nNumber == 1) return mat; int[][] tempM = sum(mat, nNumber/2); if(nNumber%2 == 0) return matMultiply(tempM, tempM); else return matMultiply(tempM, matMultiply(tempM,mat)); } public int[][] matMultiply(int[][] mA, int[][] mB){ int[][] mM = {{1, 1},{1,0}}; for(int i =0; i < 2; i++) { for(int j =0; j < 2; j++) { for(int k =0; k < 2; k++) { mM[i][j] += (mA[i][k]*mB[j][k])%1000000009; } } } return mM; } public static void main(String[] args) { // TODO Auto-generated method stub int n= 4; //1,1,2,3 int[][] mat = {{1, 1},{1,0}}; SumOfNFibonnaci sumOfNFibonnaci = new SumOfNFibonnaci(); int[][] res = sumOfNFibonnaci.sum(mat, n); System.out.println("res: "+ res[0][1]%1000000009); } }

I don't know why people said its a good explanation but I know this is worst explanation and just wasted my 22 minutes on this I am sorry to say but your speed is 1.5 x