From 1a12e0db0c196a36e7d22b660fd475f54d7cc33a Mon Sep 17 00:00:00 2001
From: Divlo <contact@divlo.fr>
Date: Thu, 5 Jan 2023 19:01:25 +0100
Subject: [PATCH] feat(solutions): add
 `first-non-repeating-character/rust/function`

---
 .../solutions/rust/function/Cargo.lock        |  7 +++
 .../solutions/rust/function/Cargo.toml        |  6 ++
 .../solutions/rust/function/README.md         |  3 +
 .../solutions/rust/function/src/main.rs       | 63 +++++++++++++++++++
 4 files changed, 79 insertions(+)
 create mode 100644 challenges/first-non-repeating-character/solutions/rust/function/Cargo.lock
 create mode 100644 challenges/first-non-repeating-character/solutions/rust/function/Cargo.toml
 create mode 100644 challenges/first-non-repeating-character/solutions/rust/function/README.md
 create mode 100644 challenges/first-non-repeating-character/solutions/rust/function/src/main.rs

diff --git a/challenges/first-non-repeating-character/solutions/rust/function/Cargo.lock b/challenges/first-non-repeating-character/solutions/rust/function/Cargo.lock
new file mode 100644
index 0000000..c8ae10e
--- /dev/null
+++ b/challenges/first-non-repeating-character/solutions/rust/function/Cargo.lock
@@ -0,0 +1,7 @@
+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 3
+
+[[package]]
+name = "rust_application"
+version = "1.0.0"
diff --git a/challenges/first-non-repeating-character/solutions/rust/function/Cargo.toml b/challenges/first-non-repeating-character/solutions/rust/function/Cargo.toml
new file mode 100644
index 0000000..a119ace
--- /dev/null
+++ b/challenges/first-non-repeating-character/solutions/rust/function/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "rust_application"
+version = "1.0.0"
+edition = "2021"
+
+[dependencies]
diff --git a/challenges/first-non-repeating-character/solutions/rust/function/README.md b/challenges/first-non-repeating-character/solutions/rust/function/README.md
new file mode 100644
index 0000000..4a0cd77
--- /dev/null
+++ b/challenges/first-non-repeating-character/solutions/rust/function/README.md
@@ -0,0 +1,3 @@
+# first-non-repeating-character/rust/function
+
+Created by [@Divlo](https://github.com/Divlo) on 5 January 2023.
diff --git a/challenges/first-non-repeating-character/solutions/rust/function/src/main.rs b/challenges/first-non-repeating-character/solutions/rust/function/src/main.rs
new file mode 100644
index 0000000..352de4d
--- /dev/null
+++ b/challenges/first-non-repeating-character/solutions/rust/function/src/main.rs
@@ -0,0 +1,63 @@
+use std::{collections::HashMap, io};
+
+#[derive(Debug, Copy, Clone)]
+pub struct CharacterOccurence {
+    pub total: usize,
+    pub first_index: usize,
+    pub value: char,
+}
+
+pub fn first_non_repeating_character(string: &str) -> String {
+    let mut characters_occurences: HashMap<char, CharacterOccurence> = HashMap::new();
+    for (index, character) in string.chars().enumerate() {
+        match characters_occurences.get(&character) {
+            Some(value) => {
+                characters_occurences.insert(
+                    character,
+                    CharacterOccurence {
+                        total: value.total + 1,
+                        ..value.clone()
+                    },
+                );
+            }
+            None => {
+                characters_occurences.insert(
+                    character,
+                    CharacterOccurence {
+                        total: 1,
+                        first_index: index,
+                        value: character,
+                    },
+                );
+            }
+        }
+    }
+    let mut result: Option<CharacterOccurence> = Option::None;
+    for (_, character_occurence) in &characters_occurences {
+        if character_occurence.total == 1 {
+            match result {
+                Some(ref mut result) => {
+                    if character_occurence.first_index < result.first_index {
+                        *result = *character_occurence;
+                    }
+                }
+                None => {
+                    result = Some(*character_occurence);
+                }
+            }
+        }
+    }
+    match result {
+        Some(result) => result.value.to_string(),
+        None => "".to_string(),
+    }
+}
+
+fn main() {
+    let mut string = String::new();
+    io::stdin()
+        .read_line(&mut string)
+        .expect("Failed to read `stdin` line.");
+    let string = string.trim();
+    println!("{}", first_non_repeating_character(&string));
+}