2015

Codejam to I/O for Women 2015

https://code.google.com/codejam/contest/9214486/dashboard

Problem A: I/O Error

Simple. Nothing to tell.

Problem B: Dreary Design

Assume the smallest number of (a, b, c) is k. Then a,b,c should be in [s, min(k, s+v)]. Let t=min(k, s+v)-s; If a=b=c=s: only 1 pair.
If a=b or b=c or c=a:

• If a=b=s, c>s then the number should be 3*t.
• If a=b>s, c=s then the number shoule be 3*t.

If a!=b, b!=c, c!=a: the number shoule be 6*t*(t-1).
Sum them, and get (3v^2+3v+1)*(k-v)+(v+1)^3.

Problem C: Power Levels

How to calculates the digits number of 9000!!!!!...!?
Just log10 it!
Binary search to find log10(9000!!!....!)<n.

Problem D: Googlander

DP.
Let's consider the first turn-down place.
for each grid (i, j), if the googlander turns from right to down here, then he only has a (i-1)*(j-1) grid to go!