[nb] Sync

exercises/dynamic-programming/22-generate-parenthesis/golang/main.go

@@ -0,0 +1,53 @@
+package main
+import (
+  "strings"
+  "container/list"
+)
+/*
+Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses.
+Example 1:
+
+Input: n = 3
+Output: ["((()))","(()())","(())()","()(())","()()()"]
+Example 2:
+  ()()(); (())();  ((())); 
+  ()(());
+  (()())
+
+Input: n = 1
+Output: ["()"]
+ 
+  ()(); (())
+
+Constraints:
+
+1 <= n <= 8
+*/
+
+func rec(input []string, left int, right int, n int, ans *[]string) {
+
+  if len(input) == 2*n {
+    *ans = append(*ans, strings.Join(input, ""))
+    return
+  }
+  if left < n {
+    input = append(input, "(")
+    rec(input, left+1, right, n, ans)
+    input = input[0:len(input)-1]
+  }
+  if right < left {
+    input = append(input, ")")
+    rec(input, left, right+1, n, ans)
+    input = input[0:len(input)-1]
+  }
+}
+
+func generateParenthesis(n int) []string {
+  var output = make([]string, 2*n)
+  var input = make([]string, 2*n)
+  rec(input, 0, 0, n, &output)
+  return output
+}
+func main() {
+  generateParenthesis(3)
+}