TheAlgorithms · sgindeed · Oct 6, 2025 · Oct 6, 2025 · Oct 6, 2025 · Oct 6, 2025
diff --git a/backtracking/m-coloring-problem.py b/backtracking/m-coloring-problem.py
@@ -0,0 +1,39 @@
+def isSafe(node, color, graph, n, col):
+    for k in range(n):
+        if graph[node][k] == 1 and col[k] == color:
+            return False
+    return True
+
+
+def solve(node, col, m, n, graph):
+    if node == n:
+        return True
+    for c in range(1, m + 1):
+        if isSafe(node, c, graph, n, col):
+            col[node] = c
+            if solve(node + 1, col, m, n, graph):
+                return True
+            col[node] = 0
+    return False
+
+
+def graphColoring(graph, m, n):
+    col = [0] * n
+    if solve(0, col, m, n, graph):
+        return True
+    return False
+
+
+if __name__ == "__main__":
+    V = int(input())
+    E = int(input())
+    graph = [[0 for _ in range(V)] for _ in range(V)]
+    for _ in range(E):
+        u, v = map(int, input().split())
+        graph[u][v] = 1
+        graph[v][u] = 1
+    m = int(input())
+    if graphColoring(graph, m, V):
+        print("True")
+    else:
+        print("False")
diff --git a/other/calc.py b/other/calc.py
@@ -0,0 +1,89 @@
+from flask import Flask, request, render_template_string
+
+app = Flask(__name__)
+
+
+def calculate(num1: float, num2: float, operation: str) -> float:
+    """
+    Perform basic arithmetic operations: add, subtract, multiply, divide.
+
+    >>> calculate(2, 3, 'add')
+    5
+    >>> calculate(5, 3, 'subtract')
+    2
+    >>> calculate(4, 2, 'multiply')
+    8
+    >>> calculate(10, 2, 'divide')
+    5.0
+    >>> calculate(5, 0, 'divide')
+    Traceback (most recent call last):
+        ...
+    ValueError: Division by zero is not allowed.
+    """
+    if operation == "add":
+        return num1 + num2
+    elif operation == "subtract":
+        return num1 - num2
+    elif operation == "multiply":
+        return num1 * num2
+    elif operation == "divide":
+        if num2 == 0:
+            raise ValueError("Division by zero is not allowed.")
+        return num1 / num2
+    else:
+        raise ValueError(f"Unknown operation: {operation}")
+
+
+# HTML template for the web interface
+template = """
+<!DOCTYPE html>
+<html>
+<head>
+    <title>Flask Calculator</title>
+    <style>
+        body { font-family: Arial, sans-serif; text-align: center; padding: 50px; background: #f7f7f7; }
+        input, select { padding: 10px; margin: 5px; width: 150px; }
+        input[type=submit] { width: auto; cursor: pointer; }
+        .result { margin-top: 20px; font-size: 1.5em; color: #27ae60; }
+        h1 { color: #2c3e50; }
+    </style>
+</head>
+<body>
+    <h1>Flask Calculator</h1>
+    <form method="POST">
+        <input type="number" name="num1" step="any" placeholder="First Number" required>
+        <input type="number" name="num2" step="any" placeholder="Second Number" required>
+        <br>
+        <select name="operation">
+            <option value="add">Add (+)</option>
+            <option value="subtract">Subtract (-)</option>
+            <option value="multiply">Multiply (×)</option>
+            <option value="divide">Divide (÷)</option>
+        </select>
+        <br>
+        <input type="submit" value="Calculate">
+    </form>
+    {% if result is not none %}
+        <div class="result">Result: {{ result }}</div>
+    {% endif %}
+</body>
+</html>
+"""
+
+
+@app.route("/", methods=["GET", "POST"])
+def home():
+    result = None
+    if request.method == "POST":
+        try:
+            num1 = float(request.form["num1"])
+            num2 = float(request.form["num2"])
+            op = request.form["operation"]
+            result = calculate(num1, num2, op)
+        except Exception as e:
+            result = str(e)
+    return render_template_string(template, result=result)
+
+
+if __name__ == "__main__":
+    app.run(debug=True)