feat(day_3): part B done in a realistic way

README.md

@@ -6,4 +6,4 @@
 | :-: | :-------------- | :----: | :----: |
 |  1  | Secret Entrance |   ⭐   |   ⭐   |
 |  2  | Gift Shop       |   ⭐   |   ⭐   |
-|  3  | Lobby           |   ⭐   |        |
+|  3  | Lobby           |   ⭐   |   ⭐   |

src/exercises/day_3.ts

@@ -48,33 +48,56 @@ export function find_largest_joltage_sum_unlimited(
   let total_joltage = 0;
 
   battey_bank_list.forEach((bank) => {
-    let max_binomial_bank = 0;
+    if (bank.length === 0) {
-
+      return;
-    for (let nc = 0; nc <= Math.pow(2, bank.length); nc += 1) {
-      // NOTE: this only works with possitibe numbers, for negative: (nc >>> 0).toString(2)
-      const binary_nc = nc.toString(2).padStart(bank.length, "0").split("");
-      // PERF: REAL dirt over here
-      if (
-        binary_nc.reduce((sum, n) => sum + (n === "1" ? 1 : 0), 0) !== LIMIT
-      ) {
-        continue;
-      }
-
-      const summatory = parseInt(bank.reduce((sum, battery, i) => {
-        const result = `${sum}${binary_nc[i] === "1" ? battery : ""}`;
-        return result;
-      }, ""));
-
-      if (summatory > max_binomial_bank) {
-        max_binomial_bank = summatory;
-      }
     }
-    total_joltage += max_binomial_bank;
+    let bank_joltage_str = "";
+    for (let limit = LIMIT - 1; limit >= 0; limit--) {
+      // [>] Find biggest number
+      let biggest_battery_index = 0;
+      let biggest_battery = bank[biggest_battery_index];
+      for (let b_index = 0; b_index < bank.length - limit; b_index++) {
+        if (bank[b_index] > biggest_battery) {
+          biggest_battery_index = b_index;
+          biggest_battery = bank[b_index];
+        }
+      }
+      // [>] Slice array
+      bank = bank.splice(biggest_battery_index + 1);
+      bank_joltage_str += biggest_battery.toString();
+    }
+    total_joltage += parseInt(bank_joltage_str);
   });
 
   return total_joltage;
 }
 
+// NOTE: this was fun but REALLY inefficient
+function find_largest_bank_joltage(bank: BatteryBank, limit: number): number {
+  let max_unlimited_bank = 0;
+  for (let nc = 0; nc <= BigInt(Math.pow(2, bank.length)); nc += 1) {
+    // NOTE: this only works with possitibe numbers, for negative: (nc >>> 0).toString(2)
+    const binary_nc = nc.toString(2).padStart(bank.length, "0").split("");
+    // PERF: REAL dirt over here
+    if (
+      binary_nc.reduce((sum, n) => sum + (n === "1" ? 1 : 0), 0) !== limit
+    ) {
+      continue;
+    }
+
+    const summatory = parseInt(bank.reduce((sum, battery, i) => {
+      const result = `${sum}${binary_nc[i] === "1" ? battery : ""}`;
+      return result;
+    }, ""));
+
+    if (summatory > max_unlimited_bank) {
+      max_unlimited_bank = summatory;
+    }
+  }
+
+  return max_unlimited_bank;
+}
+
 export async function read_battery_joltage_list(
   path: string,
 ): Promise<BatteryBank[]> {