From 91d31de2354f617812d8793665f89c2d91fccf37 Mon Sep 17 00:00:00 2001
From: Min Huang <min.huang@alumni.usc.edu>
Date: Thu, 9 Jan 2025 16:46:03 -0800
Subject: [PATCH] solves52

---
 src/52.rkt      | 24 ------------------------
 src/52.ts       | 23 +++++++++++++++++++++++
 test/52.test.ts |  7 +++++++
 3 files changed, 30 insertions(+), 24 deletions(-)
 delete mode 100644 src/52.rkt
 create mode 100644 src/52.ts
 create mode 100644 test/52.test.ts

diff --git a/src/52.rkt b/src/52.rkt
deleted file mode 100644
index a1eaa663..00000000
--- a/src/52.rkt
+++ /dev/null
@@ -1,24 +0,0 @@
-#lang racket
-(require rackunit)
-(require srfi/41)
-(require "lib/core.rkt")
-
-
-(define (same-digits? a b . more)
-  (let* ((xs (append (list a) (list b) more))
-         (ys (map integer->list xs)))
-    (andmap (curry set=? (car ys)) (cdr ys))))
-
-(define (products n)
-  (map (curry * n) (range 1 (add1 6))))
-
-(define xs
-  (stream-map products (stream-from 1)))
-
-(define ys
-  (stream-drop-while (lambda (n) (not (apply same-digits? n))) xs))
-
-(define result (car (stream-car ys)))
-
-(displayln result)
-(check-equal? result 142857)
diff --git a/src/52.ts b/src/52.ts
new file mode 100644
index 00000000..8f6846f9
--- /dev/null
+++ b/src/52.ts
@@ -0,0 +1,23 @@
+// Computes the smallest positive integer x such that 2x, 3x, 4x, 5x, and 6x, contain the same digits.
+//
+// See {@link https://projecteuler.net/problem=52}
+export default function compute() {
+  let x = 1;
+
+  while (true) {
+    const s = sort(x);
+    const isValid = [2, 3, 4, 5, 6].every(m => {
+      return sort(x * m) === s;
+    });
+
+    if (isValid) {
+      return x;
+    }
+
+    x++;
+  }
+}
+
+function sort(x: number): string {
+  return x.toString().split('').sort().join('');
+}
diff --git a/test/52.test.ts b/test/52.test.ts
new file mode 100644
index 00000000..a0b23a16
--- /dev/null
+++ b/test/52.test.ts
@@ -0,0 +1,7 @@
+import compute from '../src/52';
+
+describe('permuted multiples', () => {
+  test('problem 52', async () => {
+    expect(compute()).toBe(142857);
+  });
+});