projEuler15.ts

inputs/passing/projEuler15.ts

@@ -0,0 +1,32 @@
+export default function main() {
+  let rc = new RouteCalculator();
+  return rc.calculate(20, 20);
+}
+
+class RouteCalculator {
+  cache: number[][];
+
+  constructor() {
+    this.cache = [];
+  }
+
+  calculate(i: number, j: number) {
+    if (i < 0 || j < 0) {
+      return 0;
+    }
+
+    if (i === 0 && j === 0) {
+      return 1;
+    }
+
+    this.cache[i] ??= [];
+    let result = this.cache[i][j];
+
+    if (result === undefined) {
+      result = this.calculate(i - 1, j) + this.calculate(i, j - 1);
+      this.cache[i][j] = result;
+    }
+
+    return result;
+  }
+}