From 96254947699986c59f0dc63d69fd4b76bd3ed43e Mon Sep 17 00:00:00 2001
From: Sebastiano Tronto <sebastiano@tronto.net>
Date: Mon, 6 Jul 2026 19:08:08 +0200
Subject: Initial commit

---
 .../dynamic_range_sum_queries_1648.cpp             | 50 ++++++++++++++++++++++
 1 file changed, 50 insertions(+)
 create mode 100644 05_range_queries/dynamic_range_sum_queries_1648.cpp

(limited to '05_range_queries/dynamic_range_sum_queries_1648.cpp')

diff --git a/05_range_queries/dynamic_range_sum_queries_1648.cpp b/05_range_queries/dynamic_range_sum_queries_1648.cpp
new file mode 100644
index 0000000..ceb6b0c
--- /dev/null
+++ b/05_range_queries/dynamic_range_sum_queries_1648.cpp
@@ -0,0 +1,50 @@
+#include <algorithm>
+#include <iostream>
+#include <vector>
+
+class SumFenwickTree {
+public:
+	SumFenwickTree(int n) : a(n+1) {}
+	long long sum(int l, int r) const { return psum(r) - psum(l-1); }
+	void update(int k, long long u) { add(k, u - sum(k, k));}
+
+private:
+	std::vector<long long> a;
+
+	static int lsb(int i) { return i & -i; }
+
+	long long psum(int i) const {
+		long long s = 0;
+		while (i > 0) {
+			s += a[i];
+			i -= lsb(i);
+		}
+		return s;
+	}
+
+	void add(int k, long long d) {
+		while (k < (int)a.size()) {
+			a[k] += d;
+			k += lsb(k);
+		}
+	}
+};
+
+int main() {
+	size_t n, q;
+	std::cin >> n >> q;
+	SumFenwickTree t(n);
+	for (size_t i = 0; i < n; i++) {
+		long long x;
+		std::cin >> x;
+		t.update(i+1, x);
+	}
+	for (size_t i = 0; i < q; i++) {
+		long long x, k, u;
+		std::cin >> x >> k >> u;
+		if (x == 1)
+			t.update(k, u);
+		else
+			std::cout << t.sum(k, u) << "\n";
+	}
+}
-- 
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