Append

The built-in append function is used to dynamically add elements to a slice:

func append(slice []Type, elems ...Type) []Type

If the underlying array is not large enough, append() will create a new underlying array and point the slice to it.

Notice that append() is variadic, the following are all valid:

slice = append(slice, oneThing)
slice = append(slice, firstThing, secondThing)
slice = append(slice, anotherSlice...)

Assignment

We've been asked to "bucket" costs for an entire month into the cost occurring on each day of the month.

Complete the getCostsByDay function. It should return a slice of float64s, where each element is the total cost for that day. The length of the slice should be equal to the number of days represented in the costs slice, including any days that have no costs, up to the last day represented in the slice.

Days are numbered and start at 0.

Example

Input in day, cost format:

[]cost{
    {0, 4.0},
    {1, 2.1},
    {1, 3.1},
    {5, 2.5},
}

I would expect this result:

[]float64{
    4.0,
    5.2,
    0.0,
    0.0,
    0.0,
    2.5,
}