projEuler16.ts

inputs/passing/projEuler16.ts

@@ -0,0 +1,50 @@
+export default function main() {
+  let sbi = new SillyBigInt(1);
+  
+  for (let pow = 0; pow < 1000; pow++) {
+    sbi.add(sbi);
+  }
+
+  return sbi.data.map(digitSum).reduce((a, b) => a + b);
+}
+
+class SillyBigInt {
+  data: number[];
+
+  constructor(n: number) {
+    this.data = [n];
+  }
+
+  add(rhs: SillyBigInt) {
+    const len = Math.max(this.data.length, rhs.data.length) + 1;
+    let carry = 0;
+
+    for (let i = 0; i < len; i++) {
+      let sum = carry + (this.data[i] ?? 0) + (rhs.data[i] ?? 0);
+
+      if (sum === 0 && i >= this.data.length) {
+        continue;
+      }
+
+      if (sum >= 1000000000000000) {
+        sum -= 1000000000000000;
+        carry = 1;
+      } else {
+        carry = 0;
+      }
+
+      this.data[i] = sum;
+    }
+  }
+}
+
+function digitSum(n: number) {
+  const nStr = `${n}`;
+  let sum = 0;
+
+  for (let i = 0; i < nStr.length; i++) {
+    sum += +nStr[i];
+  }
+
+  return sum;
+}