DSA Fundamental

Day 2.
https://leetcode.com/discuss/post/6703125/google-l4-sde-3-preliminary-screening-ro-yypp/

https://drive.google.com/file/d/1iS3sm1hLg3-9T13YN9Z4PH1373_BPYJk/view

Day 3.
Recursion.

Fenwik Tree faster than Segment Tree.

Date - 23/07/25

Mathematical Terms.

Σi = (0 to 3) = sum(0+1+2+3) = 6 f(i) = sum(i^2) f(i) - f(i-1) = summationOf(i^2 - (i-1)^2) = 2i - 1 sum(10^2) = sum(9) + 2*9 - 1
sum(i^3)
f(i) - f(i-1) = i^3 - (i-1)^3

f(i) - f(i-1) = 2i - 1 f(i-1) - f(i-2) = 2(i-1) - 1 f(1) - f(0) = 2*1 - 1 = 1

g(i) = sum(f(i) - f(0)) = sum(i) Modulo.
2x + 5 = 7y + z 2x + 5 = z mod 7 (Modulo by 7)