AtCoder ABC 169 C Floating Point Fits in Ruby

Introduction

• ["AtCoder is the world's premier competitive programming site. Compete in real-time online contests, You can challenge more than 3,000 past questions at any time. ]](Https://atcoder.jp/) * I am studying programming using. Thank you, AtCoder.

This theme

AtCoder Beginner Contets C - Multiplication 3 Difficulty: 536

This theme, error due to floating point

• [Floating Point -WikiPedia](https://ja.wikipedia.org/wiki/%E6%B5%AE%E5%8B%95%E5%B0%8F%E6%95%B0%E7%82% B9% E6% 95% B0) * Ruby WA1

wa1.rb

a, b = gets.split.map(&:to_f)
puts (a * b).floor

Since it is truncated, floor is used, but WA. WA2

wa2.rb

a, b = gets.split.map(&:to_f)
puts ((a.to_i * (b * 100)) / 100).floor

Strategy to divide by 100 after100 times, failure. WA3

wa3.rb

a, b = gets.split.map(&:to_f)
puts ((a.to_i * (b * 100)) / 100).to_i

Try changing floor to to_i at the request of God. WA4

wa4.rb

a, b = gets.chomp.split
puts ((a.to_i * (b.to_f * 100).to_i) / 100)

A strategy to convert the reception from standard input into a character string. AC

ac.rb

a, b = gets.chomp.split
puts ((a.to_i * (b.gsub!('.', '').to_i).to_i) / 100)

A strategy to give up to_f by100 timesand delete the characters with the decimal point .. $ \ huge {success} $ </ font>