From 336c48be15e4ea6ee86401ee44e7ebd8062fabf9 Mon Sep 17 00:00:00 2001
From: Nuno Vieira <nunovieira220@gmail.com>
Date: Fri, 4 Dec 2020 23:14:02 +0000
Subject: Add nunovieira220 js solution to challenge 089

---
 challenge-089/nunovieira220/js/ch-1.js | 19 +++++++++
 challenge-089/nunovieira220/js/ch-2.js | 74 ++++++++++++++++++++++++++++++++++
 2 files changed, 93 insertions(+)
 create mode 100644 challenge-089/nunovieira220/js/ch-1.js
 create mode 100644 challenge-089/nunovieira220/js/ch-2.js

diff --git a/challenge-089/nunovieira220/js/ch-1.js b/challenge-089/nunovieira220/js/ch-1.js
new file mode 100644
index 0000000000..8392a0ea7a
--- /dev/null
+++ b/challenge-089/nunovieira220/js/ch-1.js
@@ -0,0 +1,19 @@
+// Input
+const N = 4;
+
+// GCD
+const gcd = (a, b) => {
+  return b == 0 ? a : gcd(b, a % b);
+}
+
+// GCD Sum
+let res = 0;
+
+for(let i = 1; i <= N; i++) {
+  for(let j = i + 1; j <= N; j++) {
+    res += gcd(i, j);
+  }
+}
+
+// Output
+console.log(res);
\ No newline at end of file
diff --git a/challenge-089/nunovieira220/js/ch-2.js b/challenge-089/nunovieira220/js/ch-2.js
new file mode 100644
index 0000000000..6158dcb27b
--- /dev/null
+++ b/challenge-089/nunovieira220/js/ch-2.js
@@ -0,0 +1,74 @@
+// Check if can have 15
+const check15 = (...args) => {
+  const zeros = args.filter(n => n === 0).length;
+  const sum = args.reduce((a, b) => a + b);
+
+  if(zeros === 1 && sum !== 15) return false;
+  if(zeros === 2 && sum <= 5) return false;
+  if(zeros === 2 && available[15 - sum] === 0) return false;
+  return true;
+};
+
+// Test if element is safe
+const isSafe = (row, col, val) => {
+  // Verify availability
+  if(!available[val]) return false;
+
+  // Verify row
+  if(!check15(res[row][0], res[row][1], res[row][2], val)) return false;
+
+  // Verify column
+  if(!check15(res[0][col], res[1][col], res[2][col], val)) return false;
+
+  // Verify y=x diagonal
+  if(row == col && !check15(res[0][0], res[1][1], res[2][2], val)) return false;
+
+  // Verify y=-x diagonal
+  if(row + col == 2 && !check15(res[0][2], res[1][1], res[2][0], val)) return false;
+
+  return true;
+};
+
+// Solve Magical Matrix
+const solve = () => {
+  let row = -1;
+  let col = -1;
+
+  for (let i = 0; i < 3; i++) {
+    index = res[i].indexOf(0);
+
+    if (index > -1) {
+      row = i;
+      col = index;
+      break;
+    }
+  }
+
+  if (col == -1) return true;
+
+  let result = false;
+
+  for(let i = 1; i < 10; i++) {
+    if (isSafe(row, col, i)) {
+      available[i] = 0;
+      res[row][col] = i;
+
+      result = solve();
+      if(result) break;
+
+      available[res[row][col]] = 1;
+      res[row][col] = 0;
+    }
+  }
+
+  return result;
+}
+
+// Magical Matrix
+const available = Array(10).fill(1);
+const res = [[0, 0, 0], [0, 0, 0], [0, 0, 0]];
+
+solve();
+
+// Output
+console.log(res);
\ No newline at end of file
-- 
cgit