Add solution for Range Sum Query - Immutable

week9/leetcode/range-sum-query-immutable.py

@@ -0,0 +1,14 @@
+class NumArray:
+
+    def __init__(self, nums: List[int]):
+        self.prefix=[0]
+        for num in nums:
+            self.prefix.append(self.prefix[-1] + num)
+    def sumRange(self, left: int, right: int) -> int:
+        return self.prefix[right+1] - self.prefix[left]
+
+
+
+# Your NumArray object will be instantiated and called as such:
+# obj = NumArray(nums)
+# param_1 = obj.sumRange(left,right)