From 5c3727b0d98335a2ba2b49e5d6754fac1b7fc914 Mon Sep 17 00:00:00 2001
From: Matej Focko <me@mfocko.xyz>
Date: Tue, 26 Mar 2024 22:08:37 +0100
Subject: [PATCH] =?UTF-8?q?rs:=20add=20=C2=AB41.=20First=20Missing=20Posit?=
 =?UTF-8?q?ive=C2=BB?=
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Signed-off-by: Matej Focko <me@mfocko.xyz>
---
 rs/first-missing-positive.rs | 21 +++++++++++++++++++++
 1 file changed, 21 insertions(+)
 create mode 100644 rs/first-missing-positive.rs

diff --git a/rs/first-missing-positive.rs b/rs/first-missing-positive.rs
new file mode 100644
index 0000000..3577ae5
--- /dev/null
+++ b/rs/first-missing-positive.rs
@@ -0,0 +1,21 @@
+impl Solution {
+    pub fn first_missing_positive(nums: Vec<i32>) -> i32 {
+        let n = nums.len() + 1;
+        let mut seen = vec![false; n];
+
+        for x in nums.into_iter() {
+            if x <= 0 || (n as i32) <= x {
+                continue;
+            }
+
+            seen[x as usize - 1] = true;
+        }
+
+        1 + seen
+            .into_iter()
+            .enumerate()
+            .find(|(_, val)| !val)
+            .expect("there's always a missing positive integer")
+            .0 as i32
+    }
+}