Add day 26

Author: MadhavBahl

day26/JavaScript/spiralCopy.js

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+/* ==================================== */
+/* ===== Matrix Spiral Copy In JS ===== */
+/* ==================================== */
+
+function spiralCopy(inputMatrix) {
+    // your code goes here
+    let outputArray = [],
+        numRow = inputMatrix.length,
+        numCol = inputMatrix[0].length;
+    
+    let topRow   = 0,
+        btmRow   = numRow - 1,
+        leftCol  = 0,
+        rightCol = numCol - 1;
+  
+    while ((topRow <= btmRow) && (leftCol <= rightCol)) {
+        for (let i=leftCol; i<=rightCol; i++) {
+            outputArray.push(inputMatrix[topRow][i]);
+        }
+        topRow++;
+        
+        for (let i=topRow; i<=btmRow; i++) {
+            outputArray.push(inputMatrix[i][rightCol]);
+        }
+        rightCol--;
+        
+        if (topRow <= btmRow) {
+            for (let i=rightCol; i>=leftCol; i--) {
+                outputArray.push(inputMatrix[btmRow][i]);
+            }
+            btmRow--;
+        }
+        
+        if (leftCol <= rightCol) {
+            for (let i=btmRow; i>=topRow; i--) {
+                outputArray.push(inputMatrix[i][leftCol]);
+            }
+            leftCol++;
+        }
+    }
+    
+    return outputArray;
+}
+
+console.log(spiralCopy([ [1,    2,   3,  4],
+             [6,    7,   8,  9],
+             [11,  12,  13,  14],
+             [16,  17,  18,  19] ]));  
+             // Should print [ 1, 2, 3, 4, 9, 14, 19, 18, 17, 16, 11, 6, 7, 8, 13, 12 ]
+
+console.log(spiralCopy([ [1,    2,   3,  4,    5],
+                         [6,    7,   8,  9,   10],
+                         [11,  12,  13,  14,  15],
+                         [16,  17,  18,  19,  20] ]));
+// Should print [ 1, 2, 3, 4, 5, 10, 15, 20, 19, 18, 17, 16, 11, 6, 7, 8, 9, 14, 13, 12 ]

day26/JavaScript/spiralGeneration.js

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+/**
+ * Spiral Matrix Generation
+ * @author MadhavBahlMD
+ * @date 24/01/2019
+ */
+
+function spiralGeneration (num) {
+    let spiral = [],
+        topRow = 0,
+        btmRow = num-1,
+        leftCol = 0,
+        rightCol = num-1,
+        count = 1;
+    
+    // Initialize the spiral matrix with zeros
+    for (let i=0; i<num; i++) {
+        let thisRow = [];
+        for (let j=0; j<num; j++) 
+            thisRow.push (0);
+        spiral.push (thisRow);
+    }
+
+    // Populate the matrix
+    while ((topRow<=btmRow) && (leftCol<=rightCol)) {
+        // Populate the top row
+        for (let i=leftCol; i<=rightCol; i++) 
+            spiral[topRow][i] = count++;
+        topRow++;
+
+        // Populate the right column
+        for (let i=topRow; i<=btmRow; i++)
+            spiral[i][rightCol] = count++;
+        rightCol--;
+
+        // Populate the bottom row IF toprow has not become greater than bottom row
+        if (topRow <= btmRow) {
+            for (let i=rightCol; i>=leftCol; i--)
+                spiral[btmRow][i] = count++;
+            btmRow--;
+        }
+
+        // Populate the left column IF rightCol has not become less than left Col
+        if (rightCol >= leftCol) {
+            for (let i=btmRow; i>=topRow; i--)
+                spiral[i][leftCol] = count++;
+            leftCol++;
+        }
+    }
+
+    // Print the result
+    console.log (spiral);
+    return spiral;
+}
+
+spiralGeneration (2);
+spiralGeneration (3);
+spiralGeneration (4);
+spiralGeneration (5);

day26/README.md

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+![cover](./cover.png)
+
+# Day 26 - Array Series Part 9: Spiral Matrix Generation and Matrix Spiral Copy
+
+## Question 1 - Spiral Matrix Generation (1D to 2D)
+
+**Question 1** -- Write a function that accepts an integer N and generates an NxN spiral matrix
+
+**Example** 
+
+```
+input: N=2
+output:
+[
+    [1, 2],
+    [4, 3]
+]
+
+input: N=3
+output:
+[
+    [1, 2, 3],
+    [8, 9, 4],
+    [7, 6, 5]
+]
+```
+
+## Question 2 - Matrix Spiral Copy (2D to 1D)
+
+Given a 2D array (matrix) inputMatrix of integers, create a function spiralCopy that copies inputMatrix’s values into a 1D array in a spiral order, clockwise. Your function then should return that array.
+
+**Example**
+
+```js
+input:  inputMatrix  = [ [1,    2,   3,  4,    5],
+                         [6,    7,   8,  9,   10],
+                         [11,  12,  13,  14,  15],
+                         [16,  17,  18,  19,  20] ]
+
+output: [1, 2, 3, 4, 5, 10, 15, 20, 19, 18, 17, 16, 11, 6, 7, 8, 9, 14, 13, 12]
+```
+
+![ques](./ques.js)
+
+## Solution to problem 1 - Spiral Matrix Generation
+
+## JavaScript Implementation
+
+### [Solution](./JavaScript/spiralGeneration.js)
+
+```js
+/**
+ * Spiral Matrix Generation
+ * @author MadhavBahlMD
+ * @date 24/01/2019
+ */
+
+function spiralGeneration (num) {
+    let spiral = [],
+        topRow = 0,
+        btmRow = num-1,
+        leftCol = 0,
+        rightCol = num-1,
+        count = 1;
+    
+    // Initialize the spiral matrix with zeros
+    for (let i=0; i<num; i++) {
+        let thisRow = [];
+        for (let j=0; j<num; j++) 
+            thisRow.push (0);
+        spiral.push (thisRow);
+    }
+
+    // Populate the matrix
+    while ((topRow<=btmRow) && (leftCol<=rightCol)) {
+        // Populate the top row
+        for (let i=leftCol; i<=rightCol; i++) 
+            spiral[topRow][i] = count++;
+        topRow++;
+
+        // Populate the right column
+        for (let i=topRow; i<=btmRow; i++)
+            spiral[i][rightCol] = count++;
+        rightCol--;
+
+        // Populate the bottom row IF toprow has not become greater than bottom row
+        if (topRow <= btmRow) {
+            for (let i=rightCol; i>=leftCol; i--)
+                spiral[btmRow][i] = count++;
+            btmRow--;
+        }
+
+        // Populate the left column IF rightCol has not become less than left Col
+        if (rightCol >= leftCol) {
+            for (let i=btmRow; i>=topRow; i--)
+                spiral[i][leftCol] = count++;
+            leftCol++;
+        }
+    }
+
+    // Print the result
+    console.log (spiral);
+    return spiral;
+}
+
+spiralGeneration (2);
+spiralGeneration (3);
+spiralGeneration (4);
+spiralGeneration (5);
+```
+
+***
+
+## Solution to problem 2 - Matrix Spiral Copy
+
+## JavaScript Implementation
+
+### [Solution](./JavaScript/spiralCopy.js)
+
+```js
+function spiralCopy(inputMatrix) {
+    // your code goes here
+    let outputArray = [],
+        numRow = inputMatrix.length,
+        numCol = inputMatrix[0].length;
+    
+    let topRow   = 0,
+        btmRow   = numRow - 1,
+        leftCol  = 0,
+        rightCol = numCol - 1;
+  
+    while ((topRow <= btmRow) && (leftCol <= rightCol)) {
+        for (let i=leftCol; i<=rightCol; i++) {
+            outputArray.push(inputMatrix[topRow][i]);
+        }
+        topRow++;
+
+        for (let i=topRow; i<=btmRow; i++) {
+            outputArray.push(inputMatrix[i][rightCol]);
+        }
+        rightCol--;
+
+        if (topRow <= btmRow) {
+            for (let i=rightCol; i>=leftCol; i--) {
+                outputArray.push(inputMatrix[btmRow][i]);
+            }
+            btmRow--;
+        }
+
+        if (leftCol <= rightCol) {
+            for (let i=btmRow; i>=topRow; i--) {
+                outputArray.push(inputMatrix[i][leftCol]);
+            }
+            leftCol++;
+        }
+    }
+    
+    return outputArray;
+}
+
+console.log(spiralCopy([ [1,    2,   3,  4],
+             [6,    7,   8,  9],
+             [11,  12,  13,  14],
+             [16,  17,  18,  19] ]));  
+             // Should print [ 1, 2, 3, 4, 9, 14, 19, 18, 17, 16, 11, 6, 7, 8, 13, 12 ]
+
+console.log(spiralCopy([ [1,    2,   3,  4,    5],
+                         [6,    7,   8,  9,   10],
+                         [11,  12,  13,  14,  15],
+                         [16,  17,  18,  19,  20] ]));
+// Should print [ 1, 2, 3, 4, 5, 10, 15, 20, 19, 18, 17, 16, 11, 6, 7, 8, 9, 14, 13, 12 ]
+```