Create 3484-design-spreadsheet.java

Author: sanajitjana

Medium/3484-design-spreadsheet.java

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+/**
+ * LeetCode Problem: Design Spreadsheet (Hypothetical Custom Problem)
+ * 
+ * Problem Link: https://leetcode.com/problems/design-spreadsheet/   (⚠️ replace with actual if exists)
+ * 
+ * Description:
+ * Implement a simple spreadsheet where:
+ * - You can set a cell with a numeric value.
+ * - You can reset a cell (making its value 0).
+ * - You can evaluate a formula string of the form "A1+B2+3", where
+ *   tokens may be integers or cell references.
+ * 
+ * Methods:
+ * Spreadsheet(int rows) -> initializes spreadsheet
+ * void setCell(String cell, int value) -> sets a cell value
+ * void resetCell(String cell) -> resets cell to 0
+ * int getValue(String formula) -> evaluates a formula string
+ * 
+ * Example:
+ * Spreadsheet obj = new Spreadsheet(3);
+ * obj.setCell("A1", 5);
+ * obj.setCell("B1", 10);
+ * obj.getValue("=A1+B1+3"); // returns 18
+ * obj.resetCell("A1");
+ * obj.getValue("=A1+B1+3"); // returns 13
+ * 
+ * Time Complexity:
+ * - setCell, resetCell: O(1) average (hash map put/get).
+ * - getValue: O(k) where k = number of terms in the formula.
+ * 
+ * Space Complexity:
+ * - O(n) for storing n cells in the map.
+ */
+
+import java.util.*;
+
+class Spreadsheet {
+
+    private Map<String, Integer> cellMap = new HashMap<>();
+    
+    public Spreadsheet(int rows) {
+        // rows parameter can be used for validation if needed
+    }
+    
+    public void setCell(String cell, int value) {
+        cellMap.put(cell, value);
+    }
+    
+    public void resetCell(String cell) {
+        cellMap.put(cell, 0);
+    }
+    
+    public int getValue(String formula) {
+        int sum = 0;
+        // skip '=' at start
+        for (String s : formula.substring(1).split("\\+")) {
+            sum += mapToValue(s.trim());
+        }
+        return sum;
+    }
+
+    private int mapToValue(String s) {
+        return Character.isLetter(s.charAt(0)) ? cellMap.getOrDefault(s, 0) : Integer.parseInt(s);
+    }
+}
+
+/**
+ * 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);
+ */