solution to 622

Author: RexWzh

src/unresolved/622.design-circular-queue.jl renamed to src/problems/622.design-circular-queue.jl

@@ -1,8 +1,8 @@
 # ---
 # title: 622. Design Circular Queue
 # id: problem622
-# author: Tian Jun
-# date: 2020-10-31
+# author: zhwang
+# date: 2022-08-04
 # difficulty: Medium
 # categories: Design, Queue
 # link: <https://leetcode.com/problems/design-circular-queue/description/>
@@ -59,5 +59,35 @@
 ## @lc code=start
 using LeetCode
 
-## add your code here:
-## @lc code=end
+mutable struct MyCircularQueue
+    len::Int
+    front::Int
+    rear::Int
+    arr::Vector{Int} ## use one extra position
+    MyCircularQueue(k::Int)  = new(k + 1, 1, 1, Vector{Int}(undef, k + 1))
+end
+
+is_full(que::MyCircularQueue) = (que.rear + 1 - que.front) % que.len == 0
+
+function en_queue(que::MyCircularQueue, val::Int)
+    is_full(que) && return false
+    que.arr[que.rear] = val
+    que.rear = que.rear % que.len + 1
+    return true
+end
+
+is_empty(que::MyCircularQueue) = que.front == que.rear
+
+function de_queue(que::MyCircularQueue)
+    is_empty(que) && return false
+    que.front = que.front % que.len + 1
+    return true
+end
+
+front(que::MyCircularQueue) = is_empty(que) ? -1 : que.arr[que.front]
+function rear(que::MyCircularQueue)
+    is_empty(que) && return -1
+    return que.arr[mod(que.rear - 2, que.len) + 1] ## use mod instead of % to avoid negative number
+end
+
+## @lc code=end

test/problems/622.design-circular-queue.jl

@@ -0,0 +1,16 @@
+@testset "622.design-circular-queue.jl" begin
+    function check622(k::Int, funcs::Vector{String}, paras::Vector, reses::Vector)
+        que = MyCircularQueue(k) 
+        all(eval(Meta.parse(func))(que, para...) == res for (func, para, res) in zip(funcs, paras, reses))
+    end
+    ## test 1
+    funcs = ["en_queue","en_queue","en_queue","en_queue","rear","is_full","de_queue","en_queue","rear"]
+    paras = [[1],[2],[3],[4],[],[],[],[4],[]]
+    reses = [true,true,true,false,3,true,true,true,4]
+    @test check622(3, funcs, paras, reses)
+    
+    funcs = ["en_queue", "rear", "front", "de_queue", "front", "de_queue", "front", "en_queue", "en_queue", "en_queue", "en_queue"]
+    paras = [[2],[],[],[],[],[],[],[4],[2],[2],[3]]
+    reses = [true,2,2,true,-1,false,-1,true,true,true,false]
+    @test check622(3, funcs, paras, reses)
+end