From 8777ff071f7bb37631baa7b6717ad29961e50911 Mon Sep 17 00:00:00 2001
From: "H.J" <thechairman@thechairman.info>
Date: Wed, 9 Oct 2024 11:36:55 -0400
Subject: sorting by language

---
 racket/leetcode/lc-217-contains-duplicate.rkt | 12 ++++++++++++
 1 file changed, 12 insertions(+)
 create mode 100644 racket/leetcode/lc-217-contains-duplicate.rkt

(limited to 'racket/leetcode/lc-217-contains-duplicate.rkt')

diff --git a/racket/leetcode/lc-217-contains-duplicate.rkt b/racket/leetcode/lc-217-contains-duplicate.rkt
new file mode 100644
index 0000000..ca8d193
--- /dev/null
+++ b/racket/leetcode/lc-217-contains-duplicate.rkt
@@ -0,0 +1,12 @@
+#lang racket
+(define/contract (contains-duplicate nums)
+  (-> (listof exact-integer?) boolean?)
+  (define nums-hash (make-hash))
+  (define (check-next-number nums)
+    (cond [(empty? nums) #false]
+          [(hash-ref nums-hash (car nums) #false) #true]
+          [else (hash-set! nums-hash (car nums) #true)
+                (check-next-number (cdr nums))]))
+  (check-next-number nums))
+
+(contains-duplicate '(1 2 3))
\ No newline at end of file
-- 
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