diff --git a/lcci/03.01.Three in One/README.md b/lcci/03.01.Three in One/README.md
index 4ba39f5bba2f3..4c467e926ee85 100644
--- a/lcci/03.01.Three in One/README.md	
+++ b/lcci/03.01.Three in One/README.md	
@@ -266,6 +266,53 @@ class TripleInOne {
  */
 ```
 
+```swift
+class TripleInOne {
+    private var cap: Int
+    private var stk: [Int]
+
+    init(_ stackSize: Int) {
+        self.cap = stackSize
+        self.stk = [Int](repeating: 0, count: cap * 3 + 3)
+    }
+
+    func push(_ stackNum: Int, _ value: Int) {
+        if stk[cap * 3 + stackNum] < cap {
+            stk[cap * stackNum + stk[cap * 3 + stackNum]] = value
+            stk[cap * 3 + stackNum] += 1
+        }
+    }
+
+    func pop(_ stackNum: Int) -> Int {
+        if isEmpty(stackNum) {
+            return -1
+        }
+        stk[cap * 3 + stackNum] -= 1
+        return stk[cap * stackNum + stk[cap * 3 + stackNum]]
+    }
+
+    func peek(_ stackNum: Int) -> Int {
+        if isEmpty(stackNum) {
+            return -1
+        }
+        return stk[cap * stackNum + stk[cap * 3 + stackNum] - 1]
+    }
+
+    func isEmpty(_ stackNum: Int) -> Bool {
+        return stk[cap * 3 + stackNum] == 0
+    }
+}
+
+/**
+ * Your TripleInOne object will be instantiated and called as such:
+ * let obj = TripleInOne(stackSize)
+ * obj.push(stackNum,value)
+ * let param_2 = obj.pop(stackNum)
+ * let param_3 = obj.peek(stackNum)
+ * let param_4 = obj.isEmpty(stackNum)
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/lcci/03.01.Three in One/README_EN.md b/lcci/03.01.Three in One/README_EN.md
index a1be1d9b41eda..62d02bde904b0 100644
--- a/lcci/03.01.Three in One/README_EN.md	
+++ b/lcci/03.01.Three in One/README_EN.md	
@@ -280,6 +280,53 @@ class TripleInOne {
  */
 ```
 
+```swift
+class TripleInOne {
+    private var cap: Int
+    private var stk: [Int]
+
+    init(_ stackSize: Int) {
+        self.cap = stackSize
+        self.stk = [Int](repeating: 0, count: cap * 3 + 3)
+    }
+
+    func push(_ stackNum: Int, _ value: Int) {
+        if stk[cap * 3 + stackNum] < cap {
+            stk[cap * stackNum + stk[cap * 3 + stackNum]] = value
+            stk[cap * 3 + stackNum] += 1
+        }
+    }
+
+    func pop(_ stackNum: Int) -> Int {
+        if isEmpty(stackNum) {
+            return -1
+        }
+        stk[cap * 3 + stackNum] -= 1
+        return stk[cap * stackNum + stk[cap * 3 + stackNum]]
+    }
+
+    func peek(_ stackNum: Int) -> Int {
+        if isEmpty(stackNum) {
+            return -1
+        }
+        return stk[cap * stackNum + stk[cap * 3 + stackNum] - 1]
+    }
+
+    func isEmpty(_ stackNum: Int) -> Bool {
+        return stk[cap * 3 + stackNum] == 0
+    }
+}
+
+/**
+ * Your TripleInOne object will be instantiated and called as such:
+ * let obj = TripleInOne(stackSize)
+ * obj.push(stackNum,value)
+ * let param_2 = obj.pop(stackNum)
+ * let param_3 = obj.peek(stackNum)
+ * let param_4 = obj.isEmpty(stackNum)
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- end -->
diff --git a/lcci/03.01.Three in One/Solution.swift b/lcci/03.01.Three in One/Solution.swift
new file mode 100644
index 0000000000000..04dd229bb6c98
--- /dev/null
+++ b/lcci/03.01.Three in One/Solution.swift	
@@ -0,0 +1,44 @@
+class TripleInOne {
+    private var cap: Int
+    private var stk: [Int]
+
+    init(_ stackSize: Int) {
+        self.cap = stackSize
+        self.stk = [Int](repeating: 0, count: cap * 3 + 3)
+    }
+
+    func push(_ stackNum: Int, _ value: Int) {
+        if stk[cap * 3 + stackNum] < cap {
+            stk[cap * stackNum + stk[cap * 3 + stackNum]] = value
+            stk[cap * 3 + stackNum] += 1
+        }
+    }
+
+    func pop(_ stackNum: Int) -> Int {
+        if isEmpty(stackNum) {
+            return -1
+        }
+        stk[cap * 3 + stackNum] -= 1
+        return stk[cap * stackNum + stk[cap * 3 + stackNum]]
+    }
+
+    func peek(_ stackNum: Int) -> Int {
+        if isEmpty(stackNum) {
+            return -1
+        }
+        return stk[cap * stackNum + stk[cap * 3 + stackNum] - 1]
+    }
+
+    func isEmpty(_ stackNum: Int) -> Bool {
+        return stk[cap * 3 + stackNum] == 0
+    }
+}
+
+/**
+ * Your TripleInOne object will be instantiated and called as such:
+ * let obj = TripleInOne(stackSize)
+ * obj.push(stackNum,value)
+ * let param_2 = obj.pop(stackNum)
+ * let param_3 = obj.peek(stackNum)
+ * let param_4 = obj.isEmpty(stackNum)
+ */
\ No newline at end of file