earlonrails · January 2, 2018 01:28 · Jan 2, 2018
diff --git a/Toeplitz.js b/Toeplitz.js
@@ -0,0 +1,39 @@
+#!/usr/bin/env node
+
+// https://www.geeksforgeeks.org/find-if-given-matrix-is-toeplitz-or-not/
+
+class Toeplitz {
+  static check(matrix) {
+    for (var i = 1; i < matrix.length - 1; i++) {
+      let row = matrix[i]
+      let prevRow = matrix[i - 1]
+      for (var j = 1; j < row.length - 1; j++) {
+        let diagonalParent = prevRow[j - 1]
+        if (diagonalParent != row[j]) {
+          return false
+        }
+      }
+    }
+    return true
+  }
+}
+
+var isToe = [
+  [6, 7, 8, 9],
+  [4, 6, 7, 8],
+  [1, 4, 6, 7],
+  [0, 1, 4, 6],
+  [2, 0, 1, 4]
+]
+
+console.log("Should be a Toeplitz:", Toeplitz.check(isToe))
+
+var isNotToe = [
+  [6, 7, 8, 9],
+  [4, 6, 6, 8],
+  [1, 2, 6, 7],
+  [0, 1, 4, 6],
+  [2, 8, 1, 4]
+]
+
+console.log("Should be a Toeplitz:", Toeplitz.check(isNotToe))