feat: add solutions to lc problem: No.0269

No.0269.Alien Dictionary

Author: taoyq1988

solution/0200-0299/0269.Alien Dictionary/README.md

@@ -288,6 +288,87 @@ public:
 };
 ```
 
+#### Go
+
+```go
+func alienOrder(words []string) string {
+	g := [26][26]bool{}
+	s := [26]bool{}
+	cnt := 0
+	n := len(words)
+	for i := 0; i < n-1; i++ {
+		for _, c := range words[i] {
+			if cnt == 26 {
+				break
+			}
+			c -= 'a'
+			if !s[c] {
+				cnt++
+				s[c] = true
+			}
+		}
+		m := len(words[i])
+		for j := 0; j < m; j++ {
+			if j >= len(words[i+1]) {
+				return ""
+			}
+			c1, c2 := words[i][j]-'a', words[i+1][j]-'a'
+			if c1 == c2 {
+				continue
+			}
+			if g[c2][c1] {
+				return ""
+			}
+			g[c1][c2] = true
+			break
+		}
+	}
+	for _, c := range words[n-1] {
+		if cnt == 26 {
+			break
+		}
+		c -= 'a'
+		if !s[c] {
+			cnt++
+			s[c] = true
+		}
+	}
+
+	inDegree := [26]int{}
+	for _, out := range g {
+		for i, v := range out {
+			if v {
+				inDegree[i]++
+			}
+		}
+	}
+	q := []int{}
+	for i, in := range inDegree {
+		if in == 0 && s[i] {
+			q = append(q, i)
+		}
+	}
+	ans := ""
+	for len(q) > 0 {
+		t := q[0]
+		q = q[1:]
+		ans += string(t + 'a')
+		for i, v := range g[t] {
+			if v {
+				inDegree[i]--
+				if inDegree[i] == 0 && s[i] {
+					q = append(q, i)
+				}
+			}
+		}
+	}
+	if len(ans) < cnt {
+		return ""
+	}
+	return ans
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/0200-0299/0269.Alien Dictionary/README_EN.md

@@ -269,6 +269,87 @@ public:
 };
 ```
 
+#### Go
+
+```go
+func alienOrder(words []string) string {
+	g := [26][26]bool{}
+	s := [26]bool{}
+	cnt := 0
+	n := len(words)
+	for i := 0; i < n-1; i++ {
+		for _, c := range words[i] {
+			if cnt == 26 {
+				break
+			}
+			c -= 'a'
+			if !s[c] {
+				cnt++
+				s[c] = true
+			}
+		}
+		m := len(words[i])
+		for j := 0; j < m; j++ {
+			if j >= len(words[i+1]) {
+				return ""
+			}
+			c1, c2 := words[i][j]-'a', words[i+1][j]-'a'
+			if c1 == c2 {
+				continue
+			}
+			if g[c2][c1] {
+				return ""
+			}
+			g[c1][c2] = true
+			break
+		}
+	}
+	for _, c := range words[n-1] {
+		if cnt == 26 {
+			break
+		}
+		c -= 'a'
+		if !s[c] {
+			cnt++
+			s[c] = true
+		}
+	}
+
+	inDegree := [26]int{}
+	for _, out := range g {
+		for i, v := range out {
+			if v {
+				inDegree[i]++
+			}
+		}
+	}
+	q := []int{}
+	for i, in := range inDegree {
+		if in == 0 && s[i] {
+			q = append(q, i)
+		}
+	}
+	ans := ""
+	for len(q) > 0 {
+		t := q[0]
+		q = q[1:]
+		ans += string(t + 'a')
+		for i, v := range g[t] {
+			if v {
+				inDegree[i]--
+				if inDegree[i] == 0 && s[i] {
+					q = append(q, i)
+				}
+			}
+		}
+	}
+	if len(ans) < cnt {
+		return ""
+	}
+	return ans
+}
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->

solution/0200-0299/0269.Alien Dictionary/Solution.go

@@ -0,0 +1,76 @@
+func alienOrder(words []string) string {
+	g := [26][26]bool{}
+	s := [26]bool{}
+	cnt := 0
+	n := len(words)
+	for i := 0; i < n-1; i++ {
+		for _, c := range words[i] {
+			if cnt == 26 {
+				break
+			}
+			c -= 'a'
+			if !s[c] {
+				cnt++
+				s[c] = true
+			}
+		}
+		m := len(words[i])
+		for j := 0; j < m; j++ {
+			if j >= len(words[i+1]) {
+				return ""
+			}
+			c1, c2 := words[i][j]-'a', words[i+1][j]-'a'
+			if c1 == c2 {
+				continue
+			}
+			if g[c2][c1] {
+				return ""
+			}
+			g[c1][c2] = true
+			break
+		}
+	}
+	for _, c := range words[n-1] {
+		if cnt == 26 {
+			break
+		}
+		c -= 'a'
+		if !s[c] {
+			cnt++
+			s[c] = true
+		}
+	}
+
+	inDegree := [26]int{}
+	for _, out := range g {
+		for i, v := range out {
+			if v {
+				inDegree[i]++
+			}
+		}
+	}
+	q := []int{}
+	for i, in := range inDegree {
+		if in == 0 && s[i] {
+			q = append(q, i)
+		}
+	}
+	ans := ""
+	for len(q) > 0 {
+		t := q[0]
+		q = q[1:]
+		ans += string(t + 'a')
+		for i, v := range g[t] {
+			if v {
+				inDegree[i]--
+				if inDegree[i] == 0 && s[i] {
+					q = append(q, i)
+				}
+			}
+		}
+	}
+	if len(ans) < cnt {
+		return ""
+	}
+	return ans
+}