Create 0303-range-sum-query-immutable.java

java/0303-range-sum-query-immutable.java

@@ -0,0 +1,23 @@
+class NumArray {
+
+    public int[] arr;
+    public NumArray(int[] nums) {
+        arr=nums;
+        for(int i=1;i<arr.length;i++){
+            arr[i]+=arr[i-1];
+        }
+    }
+
+    public int sumRange(int left, int right) {
+        if(left==0){
+            return arr[right];
+        }
+        return arr[right]-arr[left-1];
+    }
+}
+
+/**
+ * Your NumArray object will be instantiated and called as such:
+ * NumArray obj = new NumArray(nums);
+ * int param_1 = obj.sumRange(left,right);
+ */