func make_map(templ string, l int) map[string][]int {

	mapa := make(map[string][]int)

	for i := 0; i < len(templ)-l+1; i++ {
		id := templ[i : i+l]
		if val, ok := mapa[id]; ok {
			mapa[id] = append(val, i)
		} else {
			mapa[id] = []int{i}
		}
	}

	return mapa
}

func build_matrix(s_i string, templ string) [][]byte {
	l := 2
	mapa := make_map(s_i, 2)
	matrix := make([][]byte, len(s_i)-1)
	for i := range matrix {
		matrix[i] = make([]byte, len(templ)-1)
	}
	for i := 0; i < len(templ)-l+1; i++ {
		id := templ[i : i+l]
		if val, ok := mapa[id]; ok {
			for _, j := range val {
				matrix[i][j] = 1
			}
		}
	}
	return matrix
}