Data update

Task/Jacobi-symbol/JavaScript/jacobi-symbol.js

@@ -0,0 +1,52 @@
+function jacobi(n, k) {
+  if (k <= 0 || k % 2 !== 1) {
+    throw new Error("k must be positive and odd");
+  }
+  n %= k;
+  let t = 1;
+  while (n !== 0) {
+    while (n % 2 === 0) {
+      n /= 2;
+      const r = k % 8;
+      if (r === 3 || r === 5) {
+        t = -t;
+      }
+    }
+    [n, k] = [k, n]; // Swap n and k
+    if (n % 4 === 3 && k % 4 === 3) {
+      t = -t;
+    }
+    n %= k;
+  }
+  return k === 1 ? t : 0;
+}
+
+function print_table(out, kmax, nmax) {
+  let header = "n\\k|";
+  for (let k = 0; k <= kmax; ++k) {
+    header += " " + k.toString().padStart(2, ' ');
+  }
+  out.push(header);
+
+  let separator = "----";
+  for (let k = 0; k <= kmax; ++k) {
+    separator += "---";
+  }
+  out.push(separator);
+
+  for (let n = 1; n <= nmax; n += 2) {
+    let row = n.toString().padStart(2, ' ') + " |";
+    for (let k = 0; k <= kmax; ++k) {
+      row += " " + jacobi(k, n).toString().padStart(2, ' ');
+    }
+    out.push(row);
+  }
+}
+
+function main() {
+  const output = [];
+  print_table(output, 20, 21);
+  output.forEach(line => console.log(line));
+}
+
+main();