Sum and product puzzle: Difference between revisions

=={{header|Lua}}==

{{trans|C++}}

<lang lua>function print_count(t)

local cnt = 0

for k,v in pairs(t) do

cnt = cnt + 1

end

print(cnt .. ' candidates')

end

function make_pair(a,b)

local t = {}

table.insert(t, a) -- 1

table.insert(t, b) -- 2

return t

end

function setup()

local candidates = {}

for x = 2, 98 do

for y = x + 1, 98 do

if x + y <= 100 then

local p = make_pair(x, y)

table.insert(candidates, p)

end

end

end

return candidates

end

function remove_by_sum(candidates, sum)

for k,v in pairs(candidates) do

local s = v[1] + v[2]

if s == sum then

table.remove(candidates, k)

end

end

end

function remove_by_prod(candidates, prod)

for k,v in pairs(candidates) do

local p = v[1] * v[2]

if p == prod then

table.remove(candidates, k)

end

end

end

function statement1(candidates)

local unique = {}

for k,v in pairs(candidates) do

local prod = v[1] * v[2]

if unique[prod] ~= nil then

unique[prod] = unique[prod] + 1

else

unique[prod] = 1

end

end

local done

repeat

done = true

for k,v in pairs(candidates) do

local prod = v[1] * v[2]

if unique[prod] == 1 then

local sum = v[1] + v[2]

remove_by_sum(candidates, sum)

done = false

break

end

end

until done

end

function statement2(candidates)

local unique = {}

for k,v in pairs(candidates) do

local prod = v[1] * v[2]

if unique[prod] ~= nil then

unique[prod] = unique[prod] + 1

else

unique[prod] = 1

end

end

local done

repeat

done = true

for k,v in pairs(candidates) do

local prod = v[1] * v[2]

if unique[prod] > 1 then

remove_by_prod(candidates, prod)

done = false

break

end

end

until done

end

function statement3(candidates)

local unique = {}

for k,v in pairs(candidates) do

local sum = v[1] + v[2]

if unique[sum] ~= nil then

unique[sum] = unique[sum] + 1

else

unique[sum] = 1

end

end

local done

repeat

done = true

for k,v in pairs(candidates) do

local sum = v[1] + v[2]

if unique[sum] > 1 then

remove_by_sum(candidates, sum)

done = false

break

end

end

until done

end

function main()

local candidates = setup()

print_count(candidates)

statement1(candidates)

print_count(candidates)

statement2(candidates)

print_count(candidates)

statement3(candidates)

print_count(candidates)

for k,v in pairs(candidates) do

local sum = v[1] + v[2]

local prod = v[1] * v[2]

print("a=" .. v[1] .. ", b=" .. v[2] .. "; S=" .. sum .. ", P=" .. prod)

end

end

main()</lang>

{{out}}

<pre>2352 candidates

145 candidates

86 candidates

1 candidates

a=4, b=13; S=17, P=52</pre>