Question

function maxContSum(array)
    local len = #array
    local maxSum = 0
    local runningSum = array[0]
    local j = 0
    local start, finish = 0,0
    for i=0, len-1,1 do
        if runningSum > 0 then
            runningSum =runningSum + array[i]
        else 
            runningSum = array[i]
            j = i
        end
        if runningSum > maxSum then
            maxSum = runningSum
            start = j
            finish = i
        end
    print ("maxsum is ", maxSum)
   end
end

a = {-2, 2,3,4,5,-7,8,0,-1,1,2,3,4}
maxContSum(a)

This is my code.
But I get this error message:

lua: maxContSum.lua:8: attempt to compare number with nil stack
traceback:
        maxContSum.lua:8: in function 'maxContSum'
        maxContSum.lua:24: in main chunk
        [C]: ?

Need help
Thank you!

edited:
I found my problem.
Lua array index starts from 1 🙂

Answer 1

Arrays in lua are indexed from 1 and not from 0

local runningSum = array[0] should be local runningSum = array[1]
and also j = 1

and the for loop should begin from 1 to n

for i = 1, len, 1 do