func BenchmarkInversions20(b *testing.B) {
b.StopTimer()
inverse := make([]int, 1<<20)
for i := 0; i < 1<<20; i++ {
inverse[i] = 1<<20 - i
}
b.StartTimer()
for i := 0; i < b.N; i++ {
various.Inversions(inverse)
}
}
func TestInversions(t *testing.T) {
tests := []struct {
In []int
Want int
}{
{[]int{9, 8, 7, 6, 5, 4, 3, 2, 1, 0}, 45},
{[]int{0, 1, 2, 3, 4, 5, 6, 7, 8, 9}, 0},
{[]int{1, 3, 5, 2, 4, 6}, 3},
{[]int{}, 0},
}
for _, test := range tests {
count := various.Inversions(test.In)
if count != test.Want {
t.Errorf("Input array %v, expected count %v, got %v", test.In, test.Want, count)
}
}
}