RosettaCodeData/Task/Esthetic-numbers/Lua/esthetic-numbers.lua

112 lines
2.5 KiB
Lua

function to(n, b)
local BASE = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
if n == 0 then
return "0"
end
local ss = ""
while n > 0 do
local idx = (n % b) + 1
n = math.floor(n / b)
ss = ss .. BASE:sub(idx, idx)
end
return string.reverse(ss)
end
function isEsthetic(n, b)
function uabs(a, b)
if a < b then
return b - a
end
return a - b
end
if n == 0 then
return false
end
local i = n % b
n = math.floor(n / b)
while n > 0 do
local j = n % b
if uabs(i, j) ~= 1 then
return false
end
n = math.floor(n / b)
i = j
end
return true
end
function listEsths(n, n2, m, m2, perLine, all)
local esths = {}
function dfs(n, m, i)
if i >= n and i <= m then
table.insert(esths, i)
end
if i == 0 or i > m then
return
end
local d = i % 10
local i1 = 10 * i + d - 1
local i2 = i1 + 2
if d == 0 then
dfs(n, m, i2)
elseif d == 9 then
dfs(n, m, i1)
else
dfs(n, m, i1)
dfs(n, m, i2)
end
end
for i=0,9 do
dfs(n2, m2, i)
end
local le = #esths
print(string.format("Base 10: %s esthetic numbers between %s and %s:", le, math.floor(n), math.floor(m)))
if all then
for c,esth in pairs(esths) do
io.write(esth.." ")
if c % perLine == 0 then
print()
end
end
print()
else
for i=1,perLine do
io.write(esths[i] .. " ")
end
print("\n............")
for i = le - perLine + 1, le do
io.write(esths[i] .. " ")
end
print()
end
print()
end
for b=2,16 do
print(string.format("Base %d: %dth to %dth esthetic numbers:", b, 4 * b, 6 * b))
local n = 1
local c = 0
while c < 6 * b do
if isEsthetic(n, b) then
c = c + 1
if c >= 4 * b then
io.write(to(n, b).." ")
end
end
n = n + 1
end
print()
end
print()
-- the following all use the obvious range limitations for the numbers in question
listEsths(1000, 1010, 9999, 9898, 16, true)
listEsths(1e8, 101010101, 13 * 1e7, 123456789, 9, true)
listEsths(1e11, 101010101010, 13 * 1e10, 123456789898, 7, false)
listEsths(1e14, 101010101010101, 13 * 1e13, 123456789898989, 5, false)
listEsths(1e17, 101010101010101010, 13 * 1e16, 123456789898989898, 4, false)