feat(go4k): Algorithm to construct small delay times tables by abusing overlapping of different delay times.

The problem of finding a string that contains all particular substrings is the "shortest superstring problem"; it is NP-hard and analogous to traveling salesman problem. We use simple greedy search instead of trying to find true optimum. But even with these algorithm, units that use exactly the same delay times will always appear only once in the delay times table.

go4k/algorithms_test.go

@@ -0,0 +1,36 @@
+package go4k_test
+
+import (
+	"fmt"
+	"reflect"
+	"testing"
+
+	"github.com/vsariola/sointu/go4k"
+)
+
+func TestFindSuperIntArray(t *testing.T) {
+	var tests = []struct {
+		input       [][]int
+		wantSuper   []int
+		wantIndices []int
+	}{
+		{[][]int{}, []int{}, []int{}},
+		{[][]int{nil, nil}, []int{}, []int{0, 0}},
+		{[][]int{{3, 4, 5}, {1, 2, 3}}, []int{1, 2, 3, 4, 5}, []int{2, 0}},
+		{[][]int{{3, 4, 5}, {1, 2, 3}, nil}, []int{1, 2, 3, 4, 5}, []int{2, 0, 0}},
+		{[][]int{{3, 4, 5}, {1, 2, 3}, {}}, []int{1, 2, 3, 4, 5}, []int{2, 0, 0}},
+		{[][]int{{3, 4, 5}, {1, 2, 3}, {2, 3}}, []int{1, 2, 3, 4, 5}, []int{2, 0, 1}},
+		{[][]int{{1, 2, 3, 4, 5}, {1, 2, 3}}, []int{1, 2, 3, 4, 5}, []int{0, 0}},
+		{[][]int{{1, 2, 3, 4, 5}, {2, 3}}, []int{1, 2, 3, 4, 5}, []int{0, 1}},
+		{[][]int{{1, 2, 3, 4, 5}, {2, 3}, {5, 6, 7}}, []int{1, 2, 3, 4, 5, 6, 7}, []int{0, 1, 4}},
+		{[][]int{{1, 2, 3, 4}, {3, 4, 1}, {2, 3, 4, 5}}, []int{3, 4, 1, 2, 3, 4, 5}, []int{2, 0, 3}},
+	}
+	for i, tt := range tests {
+		t.Run(fmt.Sprintf("TestFindSuperIntArray %d", i), func(t *testing.T) {
+			super, indices := go4k.FindSuperIntArray(tt.input)
+			if !reflect.DeepEqual(super, tt.wantSuper) || !reflect.DeepEqual(indices, tt.wantIndices) {
+				t.Errorf("FindSuperIntArray(%v) got (%v,%v), want (%v,%v)", tt.input, super, indices, tt.wantSuper, tt.wantIndices)
+			}
+		})
+	}
+}