I have tried to make a number guessing game using ruby but it seems to be looping all over again after the user gets the correct answer, here's my code and thanks in advance!
require './input_functions'
def check (rno,input)
x = 1
while (x == 1)
y = 0
if (rno > input)
puts("Try a bigger number")
input = gets.chomp.to_i
y = y + 1
x = 1
else
if (rno < input)
puts("Try a smaller number")
input = gets.chomp.to_i
y = y + 1
x = 1
else
if(rno == input)
puts("Bingo!")
x = 0
end
end
end
end
return
end
def main
rno = rand(100)
input = read_integer("Enter an integer between 0 and 100: ")
check(rno,input,y)
times = check(rno,input,y)
puts ("You have tried " + times.to_s + " times.")
end
main
The main problems are:
You call check method two times within main method, you need to remove the first one.
You need to move y = 0 out of while loop to be able to return it.
Tried to simplify your code a bit, and you could try to improve it even more.
def check(rno, input)
x = 1
y = 0
while x == 1
if rno == input
puts "Bingo!"
x = 0
else
if rno > input
puts "Try a bigger number"
else
puts "Try a smaller number"
end
input = gets.chomp.to_i
y = y + 1
end
end
return y
end
def main
rno = rand(100)
input = read_integer("Enter an integer between 0 and 100: ")
times = check(rno, input)
puts ("You have tried " + times.to_s + " times.")
end
Related
I'm just learning Ruby :) and Im trying to create a simple prime-number program where all the primes of a number are printed.
I'm getting errors where the prime and nonprime numbers are mixed up
(ie: input of 9 will get you all nonprimes).
I'm sorry for such a beginner question - I'm struggling alot and need some help :)
puts "Enter a number please "
num = gets.chomp.to_i
i = 2
number = 2
while i < num
if number % i == 0
prime = false
end
i += 1
end
if prime == true
puts "#{number} is prime"
else
puts "#{number} is not prime"
end
number += 1
end
while i < num
if number % i == 0
prime = false
end
i += 1
end
# ...
It looks like that first end is meant to be an else.
It's easier to catch these things when you simplify your code, e.g. this method reduces to this (although there are other issues with it):
i = 2
number = 2
while i < num
(number % i).zero? ? prime = false : i += 1
puts "#{number} is #{'not ' unless prime}prime"
number += 1
end
End error is because of else
while i < num
if number % i == 0
prime = false
else
i += 1
end
if you have a short If - neater is writing it like:
if-condition ? 1 : 0
and in your case while is.. not the nicest choice - you should use range
(1...3).map{|x| puts(x) }
{} - allows multiline(with do end end)
this prints [1,2]
(1..3).map{|x| x*2 }
would be [2,4,9]
This should be enough hints of how to play around with your code without ruining the process.
The task:
The prime factors of 13195 are 5, 7, 13 and 29.
What is the largest prime factor of the number 600851475143?
The correct answer is 6857.
My code:
def prime?(n)
(2..(n-1)).each { |x| false if n % x == 0 }
true
end
x = 2
prime_factor_arr = []
number = 600_851_475_143
while x < number
if number % x == 0 && prime?(x)
prime_factor_arr << x
number = number / x
end
x += 1
end
puts prime_factor_arr.last
puts prime?(prime_factor_arr.last)
puts prime_factor_arr
In the above case, I get 1471 as the largest prime. If I change the code to:
while x < (number / x)
if number % x == 0 && prime?(x)
prime_factor_arr << x
end
x += 1
end
I get 486847. The array printed in the end is:
[71, 839, 1471, 6857, 59569, 104441, 486847]
It is not clear to me why my code does not work. Could anybody help?
For the answer to the question, Sergio is right. But the code Sergio suggests (as well as yours) will not work correctly when number is a prime itself.
A better way to write is:
def prime?(n); (2...n).none?{|x| n.%(x).zero?} end
number = 600_851_475_143
number.downto(1).find{|x| number.%(x).zero? and prime?(x)}
Try this.
def prime? n
(2..(n-1)).each { |x| return false if n % x == 0 }
true
end
n = 600_851_475_143
a = []
product_sum = 1
x = 2 # 2 is the first prime number
while product_sum < n
if n % x == 0 && prime?(x)
a << x
product_sum *= x
end
x += 1
end
puts "The answer is #{a.last}"
The prime lib (from standard lib) is very nice for Project Euler. But it takes the fun out of this one:
require "prime"
600851475143.prime_division.last.first # => 6857
I need output of Floyd triangle like:
1
0 1
1 0 1
0 1 0 1
I tried. I didn't get it exactly. Can anyone explain the logic?
This is the code I tried:
k = 0
for i in 1..5
for j in 1..5
if (i%2)==0;
k = (j%2==0) ? 1:0;
else;
k = (j%2==0) ? 0:1;
puts k,'';
end
end
puts
end
The main issue here is that in order to get the "triangle" shape of your output, you need your inner loop to increment from 1 to i instead of 1 to 5.
k = 0
for i in 1..5
for j in 1..i
if (i%2)==0
k = j + 1
else
k = j
end
print "#{k%2} "
end
puts
end
Here's a one line approach:
5.times {|line| puts (line + 1).times.with_object(""){|num, str| (num + line).even? ? (str << " 1 ") : (str << " 0 ") } }
to make it more clear:
lines = 5
lines.times do |line|
str = ""
line = line + 1 # 5.times runs from 0 to 4 and we need 1 to 5
line.times do |num|
# the condition is a bit different because I changes the code a bit
if (line + num).even?
str << " 0 "
else
str << " 1 "
end
end
puts str
end
Alright the following should work, but i hope it's readable. If you need more explanation or have specific questions let me know
i = 1
while i <= 4 do
if i%2 > 0
output = 1
else
output = 0
end
j = 1
while j <= i do
print( "#{output} " )
if output == 1
output = 0
else
output = 1
end
j+=1
end
print( "\n" )
i+=1
end
You can try following code for output you are expecting:
k = 0
for i in 1..4
for j in 1..i // inner loop code runs i times for each outer loop iteration
if (i%2)==0;
k = (j%2==0) ? 1:0;
else;
k = (j%2==0) ? 0:1;
end
print k,' ';
end
puts
end
Click Here to see output.
You can also get idea about for loops through this link.
The prefered ruby way:
layers = 4 # Change to as many layers as you want
layers.times do |i| # i starts from 0
(i + 1).times do |j| # j also starts from 0
print (i + j + 1) & 1, ' '
end
puts
end
The for way:
layers = 4
for i in 0...layers
for j in 0...(i + 1)
print (i + j + 1) & 1, ' '
end
puts
end
if i run the code, it will stop and not do anything and i am unable to type. seems to be an infinite loop.
the problem seems to be the end until loop, however if i take that out, my condition will not be met.
can anyone find a solution? i have tried all the loops that i can think of.
/. 2d array board ./
board = Array.new(10) { Array.new(10, 0) }
/. printing board ./
if board.count(5) != 5 && board.count(4) != 4 && board.count(3) != 3
for i in 0..9
for j in 0..9
board[i][j] = 0
end
end
aircraftcoord1 = (rand*10).floor
aircraftcoord2 = (rand 6).floor
aircraftalign = rand
if aircraftalign < 0.5
for i in 0..4
board[aircraftcoord2+i][aircraftcoord1] = 5
end
else
for i in 0..4
board[aircraftcoord1][aircraftcoord2+i] = 5
end
end
cruisercoord1 = (rand*10).floor
cruisercoord2 = (rand 7).floor
cruiseralign = rand
if cruiseralign < 0.5
for i in 0..3
board[cruisercoord2+i][cruisercoord1] = 4
end
else
for i in 0..3
board[cruisercoord1][cruisercoord2+i] = 4
end
end
destroyercoord1 = (rand*10).floor
destroyercoord2 = (rand 8).floor
destroyeralign = rand
if destroyeralign < 0.5
for i in 0..2
board[destroyercoord2+i][destroyercoord1] = 3
end
else
for i in 0..2
board[destroyercoord1][destroyercoord2+i] = 3
end
end
end until board.count(5) == 5 && board.count(4) == 4 && board.count(3) == 3
print " "
for i in 0..9
print i
end
puts
for i in 0..9
print i
for j in 0..9
print board[i][j]
end
puts
end
The line board.count(5) == 5 ... will never be true because board is a two-dimensional array. I can't tell what the condition should be, but it could look something like:
board[5].count(5) == 5
I'm trying to do in the Ruby program the summation of a factorial. and I can not solve. a clarification, when they run out points .... means that the logic is fine. if you get a F in one of the points, it means that the logic is wrong.
Write a program to calculate the sum of 1 + 1 / (2!) + 1 / (3!) + 1 / (4!) + .... + 1 / (n!) For a given n. Write the program in two ways: using While, For
def factorial(n)
#(n == 0) ? 1 : n * factorial(n - 1)
fact = 1
for i in 1..n
fact = fact * i
end
return fact
end
def sumatoriaWhile(n)
total = n
sumatoria = 0.0
while n > 1
total = total * (n - 1)
n = n - 1
sumatoria =sumatoria + total.to_f
end
return (1 + (1 / total.to_f)).round(2)
end
def sumatoriaFor(n)
fact = 1
sumatoria = 0.0
for i in 1..n
for j in 1..i
fact = fact * j
end
sumatoria = sumatoria + (1 / fact.to_f)
i = i + 1
end
return sumatoria.round(2)
end
#--- zona de test ----
def test_factorial
print validate(120, factorial(5))
print validate(5040, factorial(7))
print validate(362880, factorial(9))
end
def test_sumatoriaWhile
print validate(1.50, sumatoriaWhile(2))
print validate(1.83, sumatoriaWhile(3))
end
def test_sumatoriaFor
print validate(1.50, sumatoriaFor(2))
print validate(1.83, sumatoriaFor(3))
end
def validate (expected, value)
expected == value ? "." : "F"
end
def test
puts "Test program"
puts "---------------------------"
test_factorial
test_sumatoriaWhile
test_sumatoriaFor
puts " "
end
test
My friend, Thank you for your prompt response. First of all, I appreciate the help given. I am learning ruby programming and want to learn more as you and the other people. if indeed the answer is wrong. I have modified the answer. and also need to know what the function of While. and I hereby amended program again. and now I get an F on the part of WHILE.
def factorial(n)
fact = 1
for i in 1..n
fact = fact * i
end
return fact
end
def sumatoriaWhile(n)
total = n
sumatoria = 0.0
while n < 1
total = total * (n - 1)
sumatoria = sumatoria + (1.0 / total.to_f)
n = n - 1
end
return sumatoria.round(2)
end
def sumatoriaFor(n)
fact = 1
sumatoria = 0.0
for i in 1..n
fact = fact * i
sumatoria = sumatoria + (1.0 / fact.to_f)
end
return sumatoria.round(2)
end
#--- zona de test ----
def test_factorial
print validate(120, factorial(5))
print validate(5040, factorial(7))
print validate(362880, factorial(9))
end
def test_sumatoriaWhile
print validate(1.50, sumatoriaWhile(2))
print validate(1.67, sumatoriaWhile(3))
end
def test_sumatoriaFor
print validate(1.50, sumatoriaFor(2))
print validate(1.67, sumatoriaFor(3))
end
def validate (expected, value)
expected == value ? "." : "F"
end
def test
puts "Test de prueba del programa"
puts "---------------------------"
test_factorial
test_sumatoriaWhile
test_sumatoriaFor
puts " "
end
test
I have a hard time figuring out what you're doing in the summation function. Here's a straightforward function:
def sumatoriaFor(n)
return 0 if n <= 0
factorial = 1
sum = 0.0
for i in 1..n
factorial *= i
sum += 1.0 / factorial.to_f
end
return sum.round(2)
end
def sumatoriaWhile(n)
return 0 if n <= 0
i = 1
factorial = 1
sumatoria = 0.0
while i <= n
factorial *= i
sumatoria += (1.0 / factorial.to_f)
i = i + 1
end
return sumatoria.round(2)
end
The while look is straight forward too now. Also your validation is wrong:
1 + 1/2 + 1/6 ~= 1 + 0.5 + 0.17 = 1.67