From 931938ba380383cc06fd97e230c42f15703858c7 Mon Sep 17 00:00:00 2001
From: Matej Focko <mfocko@redhat.com>
Date: Sun, 11 Jun 2023 20:34:39 +0200
Subject: [PATCH] =?UTF-8?q?problems(cpp):=20add=20=E2=80=9C1146.=20Snapsho?=
 =?UTF-8?q?t=20Array=E2=80=9D?=
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Signed-off-by: Matej Focko <mfocko@redhat.com>
---
 problems/cpp/snapshot-array.cpp | 63 +++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100644 problems/cpp/snapshot-array.cpp

diff --git a/problems/cpp/snapshot-array.cpp b/problems/cpp/snapshot-array.cpp
new file mode 100644
index 0000000..f0e2962
--- /dev/null
+++ b/problems/cpp/snapshot-array.cpp
@@ -0,0 +1,63 @@
+#include <algorithm>
+#include <cassert>
+#include <map>
+#include <vector>
+
+class SnapshotArray {
+    int snap_id = 0;
+    std::vector<std::map<int, int>> arr;
+
+public:
+    SnapshotArray(int length)
+        : arr(length, std::map<int, int> { { 0, 0 } })
+    {
+    }
+
+    void set(int index, int val)
+    {
+        arr[index][snap_id] = val;
+    }
+
+    int snap()
+    {
+        return snap_id++;
+    }
+
+    int get(int index, int snap_id)
+    {
+        auto it = std::prev(arr[index].lower_bound(snap_id + 1));
+        return it == arr[index].end() ? 0 : it->second;
+    }
+};
+
+/**
+ * Your SnapshotArray object will be instantiated and called as such:
+ * SnapshotArray* obj = new SnapshotArray(length);
+ * obj->set(index,val);
+ * int param_2 = obj->snap();
+ * int param_3 = obj->get(index,snap_id);
+ */
+
+int main()
+{
+    SnapshotArray arr(3);
+    arr.set(0, 5);
+    assert(arr.snap() == 0);
+
+    arr.set(0, 6);
+    assert(arr.get(0, 0) == 5);
+    assert(arr.get(0, 1) == 6);
+
+    arr = SnapshotArray(1);
+    arr.set(0, 15);
+
+    assert(arr.snap() == 0);
+    assert(arr.snap() == 1);
+    assert(arr.snap() == 2);
+    assert(arr.get(0, 2) == 15);
+    assert(arr.snap() == 3);
+    assert(arr.snap() == 4);
+    assert(arr.get(0, 0) == 15);
+
+    return 0;
+}