0291. 单词规律 II

Author: progzc

go-leetcode/classify_algorithm/backtrack/leetcode_0291_word-pattern-ii/leetcode_0291_word-pattern-ii.go

@@ -0,0 +1,54 @@
+package leetcode_0291_word_pattern_ii
+
+// 0291. 单词规律 II
+// https://leetcode.cn/problems/word-pattern-ii/
+
+// wordPatternMatch dfs+map
+// 时间复杂度: O(mn)
+// 空间复杂度: O(n)
+// 注意：双射映射 说明需要两个map
+// 推荐题解: https://leetcode.cn/problems/word-pattern-ii/solution/hui-su-hashmapbao-cun-pi-pei-hashsetbao-645u7/
+func wordPatternMatch(pattern string, s string) bool {
+	var (
+		pLen = len(pattern)
+		sLen = len(s)
+		m    = make(map[byte]string)
+		set  = make(map[string]bool)
+		dfs  func(idx1, idx2 int) bool
+	)
+	dfs = func(idx1, idx2 int) bool {
+		if idx1 == pLen {
+			// 匹配完成
+			if idx2 == sLen {
+				return true
+			} else {
+				// s中有部分未被匹配到
+				return false
+			}
+		}
+
+		// 之前添加过
+		if v, ok := m[pattern[idx1]]; ok {
+			if idx2+len(v) <= sLen && s[idx2:idx2+len(v)] == v {
+				return dfs(idx1+1, idx2+len(v))
+			} else {
+				return false
+			}
+		}
+		// 之前未添加过
+		for i := idx2 + 1; i <= sLen; i++ {
+			str := s[idx2:i]
+			if !set[str] {
+				set[str] = true
+				m[pattern[idx1]] = str
+				if dfs(idx1+1, i) {
+					return true
+				}
+				delete(m, pattern[idx1])
+				delete(set, str)
+			}
+		}
+		return false
+	}
+	return dfs(0, 0)
+}