Time: 695 ms (51.23%), Space: 45.7 MB (37.33%) - LeetHub

Author: amanovishnu

1146-snapshot-array/1146-snapshot-array.py

@@ -0,0 +1,41 @@
+class SnapshotArray:
+
+    def __init__(self, length: int):
+        self.cur_id = 0
+        self.curVals = [0] * length
+        self.snapIdArr = [[-1] for _ in range(length)]
+        self.arrVal = [[0] for _ in range(length)]
+        self.modified = set()
+
+    def set(self, index: int, val: int) -> None:
+        if val == self.arrVal[index][-1]:
+            if index in self.modified: self.modified.remove(index)
+            return
+        self.curVals[index] = val
+        if index not in self.modified: self.modified.add(index)
+
+    def snap(self) -> int:
+        for idx in self.modified:
+            self.snapIdArr[idx].append(self.cur_id)
+            self.arrVal[idx].append(self.curVals[idx])
+        self.modified.clear()
+        self.cur_id += 1
+        return self.cur_id - 1
+
+    def get(self, index: int, snap_id: int) -> int:
+        arr = self.snapIdArr[index]
+        l, r = 0, len(arr)
+        while l < r:
+            m = (l + r) // 2
+            if arr[m] <= snap_id:
+                l = m + 1
+            else: r = m
+        return self.arrVal[index][l-1]
+        
+
+
+# Your SnapshotArray object will be instantiated and called as such:
+# obj = SnapshotArray(length)
+# obj.set(index,val)
+# param_2 = obj.snap()
+# param_3 = obj.get(index,snap_id)