bk

test.js

@@ -0,0 +1,45 @@
+var multiply = function (num1, num2) {
+  return [...num1].reverse().reduce((a, v, i) => {
+    let no = bigIntMultiply(num2, v) + "0".repeat(i);
+    return bigIntAdd([...no].reverse(), [...a].reverse());
+  }, "0");
+};
+
+const bigIntAdd = (bigInt1, bigInt2) => {
+  const lengthier = bigInt1.length >= bigInt2.length ? bigInt1 : bigInt2;
+  const shorter = lengthier === bigInt2 ? bigInt1 : bigInt2;
+  return lengthier
+    .reduce(
+      (a, v, i) => {
+        console.log(v, a[i], shorter[i]);
+        const no = +v + a[i] + shorter[i] || 0;
+        const over = ~~(no / 10);
+        a[i] = no % 10;
+        a[i + 1] = over;
+        console.log(a);
+        return a;
+      },
+      [0]
+    )
+    .reverse()
+    .join("");
+};
+
+const bigIntMultiply = (bigInt, int) => {
+  return [...bigInt]
+    .reverse()
+    .reduce(
+      (a, v, i) => {
+        const no = a[i] + v * int;
+        const over = ~~(no / 10);
+        a[i] = no % 10;
+        a[i + 1] = over;
+        return a;
+      },
+      [0]
+    )
+    .reverse()
+    .join("");
+};
+
+console.log(multiply("24", "25"));