Started Rust in Action MEAP.

3 files changed, 72 insertions, 0 deletions

diff --git a/rust-book/mathsssss/Cargo.lock b/rust-book/mathsssss/Cargo.lock
new file mode 100755
index 0000000..7ef6f32
--- /dev/null
+++ b/rust-book/mathsssss/Cargo.lock
@@ -0,0 +1,4 @@
+[[package]]
+name = "mathsssss"
+version = "0.1.0"
+
diff --git a/rust-book/mathsssss/Cargo.toml b/rust-book/mathsssss/Cargo.toml
new file mode 100755
index 0000000..201c096
--- /dev/null
+++ b/rust-book/mathsssss/Cargo.toml
@@ -0,0 +1,7 @@
+[package]
+name = "mathsssss"
+version = "0.1.0"
+authors = ["Adam Carpenter <adam.carpenter@adp.com>"]
+edition = "2018"
+
+[dependencies]
diff --git a/rust-book/mathsssss/src/main.rs b/rust-book/mathsssss/src/main.rs
new file mode 100755
index 0000000..991590b
--- /dev/null
+++ b/rust-book/mathsssss/src/main.rs
@@ -0,0 +1,61 @@
+use std::env;
+use std::collections::HashMap;
+
+fn calc_mean(numbers: &Vec<i32>) -> f32 {
+    let sum: i32 = numbers.iter().sum();
+    sum as f32 / numbers.len() as f32
+}
+
+fn calc_median(numbers: &Vec<i32>) -> i32 {
+    numbers[numbers.len() / 2]
+}
+
+fn calc_mode(numbers: &Vec<i32>) -> i32 {
+    let mut counts: HashMap<i32, i32> = HashMap::new();
+
+    for each in numbers {
+        let count = counts.entry(*each).or_insert(0);
+        *count += 1;
+    }
+
+    let mut most: i32 = 0;
+    let mut result: i32 = 0;
+
+    for (key, val) in counts.iter() {
+        
+        if val > &most {
+            most = *val;
+            result = *key;
+        }
+    }
+        
+    if most <= 1 {
+        0
+    }
+    else {
+        result
+    }
+
+}
+
+fn main() {
+    // grab numbers
+    let mut numbers: Vec<i32> = Vec::new();
+
+    for arg in env::args().skip(1) {
+        let number: i32 = arg.trim().parse()
+            .expect("error: could not parse arg");
+        numbers.push(number);
+    }
+
+    // sort list (mostly for median)
+    numbers.sort_by(|a, b| a.partial_cmp(b).unwrap());
+
+    // calculate and print results
+    let mean: f32 = calc_mean(&numbers);
+    println!("mean:   {}", mean);
+    let median: i32 = calc_median(&numbers);
+    println!("median: {}", median);
+    let mode: i32 = calc_mode(&numbers);
+    println!("mode:   {}", mode);
+}