Merge pull request #18 from Vaibhav0527/feature/Merge-Sort-Visualizer

implemented Merge-Sort-Visualizer

Author: adityacosmos24

src/algorithms/sorting/mergeSort.js

@@ -0,0 +1,64 @@
+// src/algorithms/sorting/mergeSort.js
+export function* mergeSort(array) {
+  const arr = [...array];
+  const n = arr.length;
+
+  if (n === 0) {
+    yield { type: "done", array: arr };
+    return;
+  }
+
+  function* merge(l, m, r) {
+    const left = arr.slice(l, m + 1);
+    const right = arr.slice(m + 1, r + 1);
+    let i = 0;
+    let j = 0;
+    let k = l;
+
+    while (i < left.length && j < right.length) {
+      // highlight the two elements being compared (use their original indices)
+      yield { type: "compare", indices: [l + i, m + 1 + j] };
+
+      if (left[i] <= right[j]) {
+        arr[k] = left[i];
+        yield { type: "swap", indices: [k, l + i], array: [...arr] };
+        i++;
+      } else {
+        arr[k] = right[j];
+        yield { type: "swap", indices: [k, m + 1 + j], array: [...arr] };
+        j++;
+      }
+      k++;
+    }
+
+    while (i < left.length) {
+      arr[k] = left[i];
+      yield { type: "swap", indices: [k, l + i], array: [...arr] };
+      i++;
+      k++;
+    }
+
+    while (j < right.length) {
+      arr[k] = right[j];
+      yield { type: "swap", indices: [k, m + 1 + j], array: [...arr] };
+      j++;
+      k++;
+    }
+
+    // mark merged positions as "min" to indicate they're in final place for this merge
+    for (let idx = l; idx <= r; idx++) {
+      yield { type: "min", index: idx };
+    }
+  }
+
+  function* mergeSortRec(l, r) {
+    if (l >= r) return;
+    const m = Math.floor((l + r) / 2);
+    yield* mergeSortRec(l, m);
+    yield* mergeSortRec(m + 1, r);
+    yield* merge(l, m, r);
+  }
+
+  yield* mergeSortRec(0, n - 1);
+  yield { type: "done", array: arr };
+}

src/components/sorting/MergeSortVisualizer.jsx

@@ -0,0 +1,38 @@
+import React from "react";
+
+const COLORS = {
+  default: "bg-blue-500 shadow-[0_0_10px_#3b82f6]",
+  comparing: "bg-yellow-400 shadow-[0_0_12px_#facc15]",
+  min: "bg-green-500 shadow-[0_0_12px_#22c55e]",
+  swap: "bg-red-500 shadow-[0_0_12px_#ef4444]",
+};
+
+export default function MergeSortVisualizer({ array, highlight }) {
+  const maxValue = Math.max(...array, 1); // Avoid division by zero
+  const containerHeight = 288; // px (matches h-72)
+
+  return (
+    <div className="flex items-end justify-center space-x-2 h-72 mt-10 transition-all duration-500">
+      {array.map((value, idx) => {
+        let color = COLORS.default;
+        if (highlight?.type === "compare" && highlight.indices?.includes(idx))
+          color = COLORS.comparing;
+        if (highlight?.type === "min" && highlight.index === idx)
+          color = COLORS.min;
+        if (highlight?.type === "swap" && highlight.indices?.includes(idx))
+          color = COLORS.swap;
+
+        // Normalize height relative to the maximum value
+        const height = Math.max((value / maxValue) * containerHeight, 15); // minimum 15px for visibility
+
+        return (
+          <div
+            key={idx}
+            className={`${color} w-6 transition-all duration-300 rounded-t-md`}
+            style={{ height: `${height}px` }}
+          ></div>
+        );
+      })}
+    </div>
+  );
+}

src/pages/sorting/MergeSort.jsx

@@ -0,0 +1,83 @@
+import React, { useState } from "react";
+import { Toaster } from "react-hot-toast";
+import MergeSortVisualizer from "../../components/sorting/MergeSortVisualizer";
+import { mergeSort } from "../../algorithms/sorting/mergeSort";
+
+export default function MergeSort() {
+  const [array, setArray] = useState([]);
+  const [input, setInput] = useState("");
+  const [highlight, setHighlight] = useState(null);
+  const [isRunning, setIsRunning] = useState(false);
+
+  const handleStart = async () => {
+    if (isRunning || array.length === 0) return;
+    setIsRunning(true);
+
+    const gen = mergeSort(array);
+    for (let step of gen) {
+      setHighlight(step);
+      if (step.array) setArray([...step.array]);
+      await new Promise((r) => setTimeout(r, 500));
+    }
+
+    setHighlight({ type: "done" });
+    setIsRunning(false);
+  };
+
+  const handleReset = () => {
+    setArray([]);
+    setInput("");
+    setHighlight(null);
+  };
+
+  const handleInput = (e) => {
+    setInput(e.target.value);
+    const numbers = e.target.value
+      .split(",")
+      .map((n) => parseInt(n.trim()))
+      .filter((n) => !isNaN(n));
+    setArray(numbers);
+  };
+
+  return (
+    <div className="min-h-screen bg-black text-gray-200 flex flex-col items-center p-6">
+      <Toaster position="top-center" />
+      <h1 className="text-4xl font-extrabold mb-8 text-indigo-400 drop-shadow-lg">
+        Merge Sort Visualizer
+      </h1>
+
+      <input
+        type="text"
+        value={input}
+        onChange={handleInput}
+        placeholder="Enter numbers separated by commas"
+        className="border-2 border-indigo-500 bg-gray-900 text-indigo-200 rounded-lg p-3 w-96 text-center shadow-lg focus:ring-2 focus:ring-indigo-400 outline-none"
+      />
+
+      <div className="space-x-4 mt-6">
+        <button
+          onClick={handleStart}
+          disabled={isRunning}
+          className={`${
+            isRunning
+              ? "bg-indigo-700 text-gray-300 cursor-not-allowed"
+              : "bg-indigo-600 hover:bg-indigo-500"
+          } px-6 py-2 rounded-lg text-white font-semibold shadow-md transition-all duration-300`}
+        >
+          {isRunning ? "Sorting..." : "Start Visualization"}
+        </button>
+        <button
+          onClick={handleReset}
+          className="bg-gray-700 hover:bg-gray-600 px-6 py-2 rounded-lg text-white font-semibold shadow-md transition-all duration-300"
+        >
+          Reset
+        </button>
+      </div>
+
+      <div className="mt-15">
+        <MergeSortVisualizer array={array} highlight={highlight} />
+      </div>
+
+    </div>
+  );
+}

src/pages/sorting/SortingPage.jsx

@@ -3,6 +3,7 @@ import React, { useState } from "react";
 import SelectionSort from "./SelectionSort";
 import BubbleSort from "./BubbleSort";
 import InsertionSort from "./InsertionSort";
+import MergeSort from "./MergeSort";
 
 export default function SortingPage() {
   const [selectedAlgo, setSelectedAlgo] = useState("");
@@ -17,6 +18,8 @@ export default function SortingPage() {
       case "bubble":
         return <BubbleSort />;
       // case "merge": return <MergeSort />;
+      case "merge":
+        return <MergeSort />;
       default:
         return (
           <div className="text-gray-400 text-lg mt-20 text-center">
@@ -44,6 +47,7 @@ export default function SortingPage() {
           <option value="selection">Selection Sort</option>
           <option value="bubble">Bubble Sort</option>
           <option value="insertion">Insertion Sort</option>
+          <option value="merge">Merge Sort</option>
         </select>
 
         <button