Create Spiral-matrix.js

LeetcodeProblems/Spiral-matrix.js

@@ -0,0 +1,78 @@
+/*
+https://leetcode.com/problems/spiral-matrix/description/
+
+Given a matrix of m x n elements (m rows, n columns), return all elements of the matrix in spiral order.
+
+Example 1:
+
+Input:
+[
+ [ 1, 2, 3 ],
+ [ 4, 5, 6 ],
+ [ 7, 8, 9 ]
+]
+Output: [1,2,3,6,9,8,7,4,5]
+Example 2:
+
+Input:
+[
+  [1, 2, 3, 4],
+  [5, 6, 7, 8],
+  [9,10,11,12]
+]
+Output: [1,2,3,4,8,12,11,10,9,5,6,7]
+*/
+
+/**
+ * @param {number[][]} matrix
+ * @return {number[]}
+ */
+
+var spiralOrder = function(matrix) {
+    if(matrix.length === 0)
+        return [];
+    var retArray = [];
+    const rowLength = matrix.length;
+    const colLength = matrix[0].length;
+    const countRectangles = Math.ceil(Math.min(colLength, rowLength)/2)
+    for(var i = 0; i < countRectangles; i++) {
+        printRect(matrix, i, rowLength, colLength, retArray);
+    }
+    return retArray;
+};
+
+var printRect = function(matrix, i, rowLength, colLength, retArray) {
+    const firstRow = i;
+    const firstCol = i;
+    const lastRow = rowLength - i - 1;
+    const lastCol = colLength - i - 1;
+
+    for(var col = firstCol; col <= lastCol; col++) {
+        retArray.push(matrix[firstRow][col]);
+    }
+    for(var row = firstRow + 1; row <= lastRow; row++) {
+        retArray.push(matrix[row][lastCol]);
+    }
+    if(firstRow === lastRow || firstCol === lastCol) {
+        return;
+    }
+    for(var col = lastCol - 1; col >= firstCol; col--) {
+        retArray.push(matrix[lastRow][col]);
+    }
+    for(var row = lastRow - 1; row > firstRow; row--) {
+        retArray.push(matrix[row][firstCol]);
+    }
+}
+
+var main = function() {
+  const matrix = [
+   [ 1, 2, 3 ],
+   [ 4, 5, 6 ],
+   [ 7, 8, 9 ]
+  ]
+
+  console.log(spiralOrder(matrix));
+}
+
+main();
+module.exports.main = main;