212 1432ms 26.06%

212_word_search_ii/word_search_ii.go

@@ -0,0 +1,85 @@
+package word_search_ii
+
+// https://leetcode.com/problems/word-search-ii
+
+// level: 3
+// time: unknown 1432ms 26.06%
+// space: O(n) 2.6M 62.42%
+
+//leetcode submit region begin(Prohibit modification and deletion)
+
+type Node struct {
+	char byte
+	word string
+	next map[byte]*Node
+}
+
+type Trie struct {
+	root *Node
+}
+
+func Constructor() Trie {
+	root := &Node{byte(0), "", make(map[byte]*Node)}
+	return Trie{root}
+}
+
+func (t *Trie) Add(word string) {
+	cur := t.root
+	for i := 0; i < len(word); i++ {
+		char := word[i]
+		if cur.next[char] == nil {
+			cur.next[char] = &Node{char, "", make(map[byte]*Node)}
+		}
+		cur = cur.next[char]
+	}
+	cur.word = word
+}
+
+type Result struct {
+	board   [][]byte
+	result  map[string]bool
+	visited map[[2]int]bool
+}
+
+func (r *Result) search(x, y int, node *Node) {
+	if x < 0 || y < 0 || y >= len(r.board) || x >= len(r.board[0]) || r.visited[[2]int{x, y}] {
+		return
+	}
+	r.visited[[2]int{x, y}] = true
+	for char, n := range node.next {
+		if char != r.board[y][x] {
+			continue
+		}
+		r.search(x+1, y, n)
+		r.search(x-1, y, n)
+		r.search(x, y+1, n)
+		r.search(x, y-1, n)
+
+		if n.word != "" {
+			r.result[n.word] = true
+			continue
+		}
+	}
+	r.visited[[2]int{x, y}] = false
+}
+
+func findWords(board [][]byte, words []string) []string {
+	t := Constructor()
+	for _, word := range words {
+		t.Add(word)
+	}
+	r := &Result{board, map[string]bool{}, map[[2]int]bool{}}
+	for j := 0; j < len(board); j++ {
+		for i := 0; i < len(board[j]); i++ {
+			r.search(i, j, t.root)
+		}
+	}
+	ret, i := make([]string, len(r.result)), 0
+	for s := range r.result {
+		ret[i] = s
+		i++
+	}
+	return ret
+}
+
+//leetcode submit region end(Prohibit modification and deletion)

212_word_search_ii/word_search_ii_test.go

@@ -0,0 +1,76 @@
+package word_search_ii
+
+import (
+	"reflect"
+	"sort"
+	"testing"
+)
+
+func Test_findWords(t *testing.T) {
+	type args struct {
+		board [][]byte
+		words []string
+	}
+	tests := []struct {
+		name string
+		args args
+		want []string
+	}{
+		{
+			name: "test1",
+			args: args{[][]byte{
+				{'o', 'a', 'a', 'n'},
+				{'e', 't', 'a', 'e'},
+				{'i', 'h', 'k', 'r'},
+				{'i', 'f', 'l', 'v'},
+			}, []string{"oath", "pea", "eat", "rain"}},
+			want: []string{"eat", "oath"},
+		},
+		{
+			name: "test2",
+			args: args{[][]byte{
+				{'a', 'b'},
+				{'c', 'd'},
+			}, []string{"abcd"}},
+			want: []string{},
+		},
+		{
+			name: "test3",
+			args: args{[][]byte{{'a'}}, []string{"a"}},
+			want: []string{"a"},
+		},
+		{
+			name: "test4",
+			args: args{[][]byte{
+				{'o', 'a', 'b', 'n'},
+				{'o', 't', 'a', 'e'},
+				{'a', 'h', 'k', 'r'},
+				{'a', 'f', 'l', 'v'},
+			}, []string{"oa", "oaa"}},
+			want: []string{"oa", "oaa"},
+		},
+		{
+			name: "test5",
+			args: args{[][]byte{{'a', 'a'}}, []string{"aaa"}},
+			want: []string{},
+		},
+		{
+			name: "test6",
+			args: args{[][]byte{
+				{'a', 'b'},
+				{'c', 'd'},
+			}, []string{"abdca"}},
+			want: []string{},
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := findWords(tt.args.board, tt.args.words)
+			sort.Strings(got)
+			sort.Strings(tt.want)
+			if !reflect.DeepEqual(got, tt.want) {
+				t.Errorf("findWords() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}