roman numerals

roman-numerals/Cargo.toml

@@ -0,0 +1,6 @@
+[package]
+name = "roman-numerals"
+version = "0.1.0"
+edition = "2021"
+
+[dependencies]

roman-numerals/src/main.rs

@@ -0,0 +1,70 @@
+use std::collections::HashMap;
+use std::io::{stdin,stdout,Write};
+
+fn input() -> String{
+    let mut s=String::new();
+    let _=stdout().flush();
+    stdin().read_line(&mut s).expect("Did not enter a correct string");
+    if let Some('\n')=s.chars().next_back() {
+        s.pop();
+    }
+    if let Some('\r')=s.chars().next_back() {
+        s.pop();
+    }
+    return s;
+}
+fn main() {
+    let mut numerals: HashMap<String, u64> = HashMap::new();
+
+    numerals.insert("I".to_string(), 1);
+    numerals.insert("V".to_string(), 5);
+    numerals.insert("X".to_string(), 10);
+    numerals.insert("L".to_string(), 50);
+    numerals.insert("C".to_string(), 100);
+    numerals.insert("D".to_string(), 500);
+    numerals.insert("M".to_string(), 1000);
+    
+    let number = input();
+    let mut value: u64 = 4000;
+    let mut sum: u64 = 0;
+    let mut iteration = 0;
+
+    let mut skip_next = false;
+
+    let mut vector: Vec<String> = Vec::new();
+
+    for char in number.chars() {
+        vector.push(char.to_string());
+    };
+
+    for digit in vector {
+        if let Some(next_value) = numerals.get(&digit) {
+            if iteration > 0 && skip_next == false {
+                 //println!("{}", skip_next);
+                 //print!("{}:   ", iteration);
+                 if *next_value > value {
+                    sum = sum + (*next_value - value);
+                    //println!("{} = sum + ({} - {})", sum, *next_value, value);
+                    skip_next = true;
+                    value = *next_value;
+                    continue;
+                 }
+                 else {
+                    sum = sum + value;
+                    //println!("{} = sum + {}", sum, value);
+                 }
+            }
+            value = *next_value;
+            if skip_next {
+                skip_next = false;
+            }
+        } else {
+            println!("digit {} does not exist (My roman numerals only go up to M)!", digit);
+        }
+        iteration += 1;
+    }
+    if skip_next == false {
+        sum = sum + value;
+    }
+    println!("{}",sum);
+}