Add problem 303 .

1 files changed, 26 insertions, 0 deletions

diff --git a/cpp/303.cpp b/cpp/303.cpp
new file mode 100644
index 0000000..74aea3c
--- /dev/null
+++ b/cpp/303.cpp
@@ -0,0 +1,26 @@
+#include <vector>
+
+using std::vector;
+
+class NumArray
+{
+private:
+    vector<int> prefix_sums;
+
+public:
+    NumArray(vector<int> &nums)
+    {
+        prefix_sums.push_back(0);
+        int sum = 0;
+        for (auto num : nums)
+        {
+            sum += num;
+            prefix_sums.push_back(sum);
+        }
+    }
+
+    int sumRange(int i, int j)
+    {
+        return prefix_sums[j + 1] - prefix_sums[i];
+    }
+};