From 342e23a2947b52e4f795b0de7c6823ded628d16d Mon Sep 17 00:00:00 2001
From: Libin YANG <contact@yanglibin.info>
Date: Fri, 19 Sep 2025 06:54:25 +0800
Subject: [PATCH] feat: add solution to lc problem: No.3484

---
 .../3484.Design Spreadsheet/README.md         | 36 +++++++++++++++++++
 .../3484.Design Spreadsheet/README_EN.md      | 36 +++++++++++++++++++
 .../3484.Design Spreadsheet/Solution.cs       | 31 ++++++++++++++++
 3 files changed, 103 insertions(+)
 create mode 100644 solution/3400-3499/3484.Design Spreadsheet/Solution.cs

diff --git a/solution/3400-3499/3484.Design Spreadsheet/README.md b/solution/3400-3499/3484.Design Spreadsheet/README.md
index 21ec3f99602f7..ba2fc0d592882 100644
--- a/solution/3400-3499/3484.Design Spreadsheet/README.md	
+++ b/solution/3400-3499/3484.Design Spreadsheet/README.md	
@@ -312,6 +312,42 @@ impl Spreadsheet {
 }
 ```
 
+#### C#
+
+```cs
+public class Spreadsheet {
+    private Dictionary<string, int> d = new Dictionary<string, int>();
+
+    public Spreadsheet(int rows) {
+    }
+
+    public void SetCell(string cell, int value) {
+        d[cell] = value;
+    }
+
+    public void ResetCell(string cell) {
+        d.Remove(cell);
+    }
+
+    public int GetValue(string formula) {
+        int ans = 0;
+        foreach (string cell in formula.Substring(1).Split('+')) {
+            ans += char.IsDigit(cell[0]) ? int.Parse(cell)
+                                         : (d.ContainsKey(cell) ? d[cell] : 0);
+        }
+        return ans;
+    }
+}
+
+/**
+ * Your Spreadsheet object will be instantiated and called as such:
+ * Spreadsheet obj = new Spreadsheet(rows);
+ * obj.SetCell(cell,value);
+ * obj.ResetCell(cell);
+ * int param_3 = obj.GetValue(formula);
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
diff --git a/solution/3400-3499/3484.Design Spreadsheet/README_EN.md b/solution/3400-3499/3484.Design Spreadsheet/README_EN.md
index 57ae6bf843f4e..106261b730930 100644
--- a/solution/3400-3499/3484.Design Spreadsheet/README_EN.md	
+++ b/solution/3400-3499/3484.Design Spreadsheet/README_EN.md	
@@ -310,6 +310,42 @@ impl Spreadsheet {
 }
 ```
 
+#### C#
+
+```cs
+public class Spreadsheet {
+    private Dictionary<string, int> d = new Dictionary<string, int>();
+
+    public Spreadsheet(int rows) {
+    }
+
+    public void SetCell(string cell, int value) {
+        d[cell] = value;
+    }
+
+    public void ResetCell(string cell) {
+        d.Remove(cell);
+    }
+
+    public int GetValue(string formula) {
+        int ans = 0;
+        foreach (string cell in formula.Substring(1).Split('+')) {
+            ans += char.IsDigit(cell[0]) ? int.Parse(cell)
+                                         : (d.ContainsKey(cell) ? d[cell] : 0);
+        }
+        return ans;
+    }
+}
+
+/**
+ * Your Spreadsheet object will be instantiated and called as such:
+ * Spreadsheet obj = new Spreadsheet(rows);
+ * obj.SetCell(cell,value);
+ * obj.ResetCell(cell);
+ * int param_3 = obj.GetValue(formula);
+ */
+```
+
 <!-- tabs:end -->
 
 <!-- solution:end -->
diff --git a/solution/3400-3499/3484.Design Spreadsheet/Solution.cs b/solution/3400-3499/3484.Design Spreadsheet/Solution.cs
new file mode 100644
index 0000000000000..e01b30e25d7af
--- /dev/null
+++ b/solution/3400-3499/3484.Design Spreadsheet/Solution.cs	
@@ -0,0 +1,31 @@
+public class Spreadsheet {
+    private Dictionary<string, int> d = new Dictionary<string, int>();
+
+    public Spreadsheet(int rows) {
+    }
+
+    public void SetCell(string cell, int value) {
+        d[cell] = value;
+    }
+
+    public void ResetCell(string cell) {
+        d.Remove(cell);
+    }
+
+    public int GetValue(string formula) {
+        int ans = 0;
+        foreach (string cell in formula.Substring(1).Split('+')) {
+            ans += char.IsDigit(cell[0]) ? int.Parse(cell)
+                                         : (d.ContainsKey(cell) ? d[cell] : 0);
+        }
+        return ans;
+    }
+}
+
+/**
+ * Your Spreadsheet object will be instantiated and called as such:
+ * Spreadsheet obj = new Spreadsheet(rows);
+ * obj.SetCell(cell,value);
+ * obj.ResetCell(cell);
+ * int param_3 = obj.GetValue(formula);
+ */