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Showing posts from February, 2015

Thinking of Project Euler after a month from starting time

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It took a month to solve problems 1 to 67. And I want to tell you the advantage of it
1. I learned math a lot from it. 2. Simplify my dirty source. 3. Clearly thinking coumputer language. 4. some algorithm
My first plan is to solve one hundred problems. I can do it~!!!
:)

Solved 54 problem

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this is about the rule of poker

I wrote ideas and logic on my book and
coded.

My source was to get the real answer and
later on I will change my code to have no duplication code!!!







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Sieve of Eratoshenes

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A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.

I want to find Prime number from 2, 3, .... To  N

First we need to make
new int [N];



like this ~ we visit all number of Array.

below is my code



1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31/** * 1== prime * * @return */publicstaticint[]isPrimeFromSieve(int limit){int[] val =newint[limit];for(int i =2; i < val.length; i++){if(val[i]==0){ val[i]=1; checkMultiple(i, val);}}return val;}privatestaticvoidcheckMultiple(int a,int[] val){for(int i =2; i < val.length; i++){int num = a * i;if(num >= val.length){return;} val[num]=2;}}

Level 2 Upgraded

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I had very hard time to completely solved 50problems.
What I got from those problems is clearly coding skill.
I think it is very good to think. I will do more and more 

My progress euler 2days

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I started it 02/06/2014

If you are interested in Algorithm and math
visit this site is https://projecteuler.net/

really fun and interesting

My 2days solved is

Topcoder Srm 626 div2 500 problem

When I tried to solve this problem, I didn't exactly know about expected value.
know I can liite understand it

problem is get expected value if A value is larger than B


A. 2 sided
B. 2 sided

case is (2,1)
so expected value is 2

A. 4-sided
B. 2-sided

(4,1) (4,2) (3,1) (3,2) (2,1)
4+4+3+3+2 / 5 = 3.2

this is what i learn from this problem.

My one plan for this year~

these days. I started to study algorithm. I am 32years old. my first thought was too old to learn algorithm.
But I decided to study it.
I know this comment and believe it.

Beginning is half done

I will do my best.

and also I will get over 1500 ratings in Topcoder.
Now my rating is 568.

Don't worry~!!

DO IT DO IT.