lua实现堆排序

堆排序：

local function swap(t, i, j)
    local temp = t[i]
    t[i] = t[j]
    t[j] = temp
end

local function heapInsert(t, i)
   -- i 下标的 父下标为 i / 2
    while i > 1 and t[i] > t[i // 2] do
        swap(t, i, i // 2)
        i = i // 2
    end

end
  
  
local function heapify(t, i, size)
    local left = i * 2
    while left < size do
        local largest = (left + 1 < size and t[left + 1] > t[left]) and left + 1 or left
        largest = t[i] > t[largest] and i or largest
        if largest == i then return end
        swap(t, i, largest)
        i = largest
        left = i * 2
    end
end
  
 
function heapSort(t)
    if(t and #t < 2) then
        return
    end
    
    for i = 1, #t do
        heapInsert(t, i)
    end
    
    local size = #t
    swap(t, 1, size)

    while size > 1 do
        heapify(t, 1, size)
        size = size - 1
        swap(t, 1, size)
    end
end

t = {1, 34, 435, 2, 6, -234, 324, -4, 0}
print(table.concat(t, ","))
heapSort(t)
print(table.concat(t, ","))

----- 1,34,435,2,6,-234,324,-4,0
----- -234,-4,0,1,2,6,34,324,435