check for equality on slices without order

Issue

I am trying to find a solution to check for equality in 2 slices. Unfortanely, the answers I have found require values in the slice to be in the same order. For example, http://play.golang.org/p/yV0q1_u3xR evaluates equality to false.
I want a solution that lets []string{"a","b","c"} == []string{"b","a","c"} evaluate to true.
MORE EXAMPLES
[]string{"a","a","c"} == []string{"c","a","c"} >>> false
[]string{"z","z","x"} == []string{"x","z","z"} >>> true

Solution

Here is an alternate solution, though perhaps a bit verbose:

func sameStringSlice(x, y []string) bool {
    if len(x) != len(y) {
        return false
    }
    // create a map of string -> int
    diff := make(map[string]int, len(x))
    for _, _x := range x {
        // 0 value for int is 0, so just increment a counter for the string
        diff[_x]++
    }
    for _, _y := range y {
        // If the string _y is not in diff bail out early
        if _, ok := diff[_y]; !ok {
            return false
        }
        diff[_y] -= 1
        if diff[_y] == 0 {
            delete(diff, _y)
        }
    }
    return len(diff) == 0
}

Try it on the Go Playground

Answered By – sberry

Answer Checked By – Terry (GoLangFix Volunteer)

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