From 52d2e3e7a42e62a5233577f36235a0c9e93d696e Mon Sep 17 00:00:00 2001
From: Matej Focko <mfocko@redhat.com>
Date: Sun, 14 Jan 2024 16:33:38 +0100
Subject: [PATCH] =?UTF-8?q?rs:=20add=20=E2=80=9C1657.=20Determine=20if=20T?=
 =?UTF-8?q?wo=20Strings=20Are=20Close=E2=80=9D?=
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Signed-off-by: Matej Focko <mfocko@redhat.com>
---
 rs/determine-if-two-strings-are-close.rs | 39 ++++++++++++++++++++++++
 1 file changed, 39 insertions(+)
 create mode 100644 rs/determine-if-two-strings-are-close.rs

diff --git a/rs/determine-if-two-strings-are-close.rs b/rs/determine-if-two-strings-are-close.rs
new file mode 100644
index 0000000..e1c9c99
--- /dev/null
+++ b/rs/determine-if-two-strings-are-close.rs
@@ -0,0 +1,39 @@
+use std::convert::TryFrom;
+
+impl Solution {
+    fn freqs(word: &str) -> Vec<usize> {
+        let mut f = vec![0; 26];
+
+        let zero = u8::try_from('a').unwrap();
+        for c in word.chars().filter_map(|c| match u8::try_from(c) {
+            Ok(val) => Some(val),
+            _ => None,
+        }) {
+            f[(c - zero) as usize] += 1;
+        }
+
+        f
+    }
+
+    fn mask(f: &[usize]) -> i32 {
+        let mut m = 0;
+
+        for c in f {
+            m = (m << 1) | if *c > 0 { 1 } else { 0 };
+        }
+
+        m
+    }
+
+    pub fn close_strings(word1: String, word2: String) -> bool {
+        let mut f1 = Solution::freqs(&word1);
+        let m1 = Solution::mask(&f1);
+        f1.sort();
+
+        let mut f2 = Solution::freqs(&word2);
+        let m2 = Solution::mask(&f2);
+        f2.sort();
+
+        m1 == m2 && f1 == f2
+    }
+}