Data update

Task/Pascals-triangle-Puzzle/JavaScript/pascals-triangle-puzzle.js

@@ -0,0 +1,102 @@
+class Matrix {
+  constructor(...lists) {
+    if (lists.length === 1 && Array.isArray(lists[0][0])) {
+      this.matrix = lists[0];
+    } else {
+      this.matrix = lists;
+    }
+  }
+
+  toString() {
+    return JSON.stringify(this.matrix);
+  }
+
+  determinant() {
+    if (this.matrix.length === 1) {
+      return this.get(0, 0);
+    }
+    if (this.matrix.length === 2) {
+      return this.get(0, 0) * this.get(1, 1) - this.get(0, 1) * this.get(1, 0);
+    }
+    let sum = 0;
+    let sign = 1;
+    for (let i = 0; i < this.matrix.length; i++) {
+      sum += sign * this.get(0, i) * this.coFactor(0, i).determinant();
+      sign *= -1;
+    }
+    return sum;
+  }
+
+  coFactor(row, col) {
+    const mat = [];
+    for (let i = 0; i < this.matrix.length; i++) {
+      if (i === row) {
+        continue;
+      }
+      const list = [];
+      for (let j = 0; j < this.matrix.length; j++) {
+        if (j === col) {
+          continue;
+        }
+        list.push(this.get(i, j));
+      }
+      mat.push(list);
+    }
+    return new Matrix(mat);
+  }
+
+  replaceColumn(b, column) {
+    const mat = [];
+    for (let row = 0; row < this.matrix.length; row++) {
+      const list = [];
+      for (let col = 0; col < this.matrix.length; col++) {
+        let value = this.get(row, col);
+        if (col === column) {
+          value = b[row];
+        }
+        list.push(value);
+      }
+      mat.push(list);
+    }
+    return new Matrix(mat);
+  }
+
+  get(row, col) {
+    return this.matrix[row][col];
+  }
+}
+
+function cramersRule(matrix, b) {
+  const denominator = matrix.determinant();
+  const result = [];
+  for (let i = 0; i < b.length; i++) {
+    result.push(matrix.replaceColumn(b, i).determinant() / denominator);
+  }
+  return result;
+}
+
+function main() {
+  const mat = new Matrix(
+    [1, 0, 0, 0, 0, 0, 0, 0, -1, 0, 0],
+    [0, 1, 0, 0, 0, 0, 0, 0, 0, -1, 0],
+    [0, 0, 0, 0, 0, 0, 0, 0, -1, 1, -1],
+    [0, 0, 1, 0, 0, 0, 0, 0, 0, -1, 0],
+    [0, 0, 0, 1, 0, 0, 0, 0, 0, 0, -1],
+    [1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+    [0, 1, 1, 0, -1, 0, 0, 0, 0, 0, 0],
+    [0, 0, 1, 1, 0, -1, 0, 0, 0, 0, 0],
+    [0, 0, 0, 0, -1, 0, 1, 0, 0, 0, 0],
+    [0, 0, 0, 0, 1, 1, 0, -1, 0, 0, 0],
+    [0, 0, 0, 0, 0, 0, 1, 1, 0, 0, 0]
+  );
+
+  const b = [11, 11, 0, 4, 4, 40, 0, 0, 40, 0, 151];
+  const solution = cramersRule(mat, b);
+
+  console.log("Solution =", solution);
+  console.log(`X = ${solution[8].toFixed(2)}`);
+  console.log(`Y = ${solution[9].toFixed(2)}`);
+  console.log(`Z = ${solution[10].toFixed(2)}`);
+}
+
+main();