From 6486cccd5cf558bb876830928afe472bc1fccccf Mon Sep 17 00:00:00 2001
From: "Cpt. Captain" <nilskoch94@gmail.com>
Date: Fri, 25 May 2018 23:36:13 +0200
Subject: [PATCH] solved the rabbit problem

---
 .gitignore          |   2 +
 rabbits/Cargo.toml  |   6 +++
 rabbits/src/main.rs | 103 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 111 insertions(+)
 create mode 100644 rabbits/Cargo.toml
 create mode 100644 rabbits/src/main.rs

diff --git a/.gitignore b/.gitignore
index fb581c9..f446af5 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,4 @@
 tally/target/
 tally/Cargo.lock
+rabbits/target/
+rabbits/Cargo.lock
diff --git a/rabbits/Cargo.toml b/rabbits/Cargo.toml
new file mode 100644
index 0000000..cf38f98
--- /dev/null
+++ b/rabbits/Cargo.toml
@@ -0,0 +1,6 @@
+[package]
+name = "rabbits"
+version = "0.1.0"
+authors = ["Cpt. Captain <nilskoch94@gmail.com>"]
+
+[dependencies]
diff --git a/rabbits/src/main.rs b/rabbits/src/main.rs
new file mode 100644
index 0000000..2dc51f4
--- /dev/null
+++ b/rabbits/src/main.rs
@@ -0,0 +1,103 @@
+// https://www.reddit.com/r/dailyprogrammer/comments/7s888w/20180122_challenge_348_easy_the_rabbit_problem/
+
+use std::{thread, time, io};
+
+fn init(male: i128, female: i128, needed_alive: i128) -> ([i128; 96], [i128; 96], i128){
+    
+    let mut m: [i128; 96] = [0; 96];
+    let mut f: [i128; 96] = [0; 96];
+    m[2] = male;
+    f[2] = female;
+    return (m, f, needed_alive);
+}
+
+
+// reproduce, by letting all females 4 months and over have 9 female and 5 male descendants
+// fn reproduce(m_pop: [i128; 96], f_pop: [i128; 96]) -> ([i128; 96], [i128;96], i128, i128) {
+fn reproduce(m_pop: [i128; 96], f_pop: [i128; 96]) -> (i128, i128) {
+    let mut res_m = 0;
+    let mut res_f = 0;
+    let f_iter = f_pop.iter().enumerate();
+    for (i, count) in f_iter {
+        if i < 95 && i > 3{
+            // res_f[0] = res_f[0] + count * 9;
+            // res_m[0] = res_m[0] + count * 5;
+            res_m = res_m + count * 5;
+            res_f = res_f + count * 9;
+        }
+    }
+    return (res_m, res_f);
+}
+
+// age the bunny population by shifting the array one to the right
+fn age(m_pop: [i128; 96], f_pop: [i128; 96], new_males: i128, new_females: i128) -> ([i128; 96], [i128; 96]){
+    let mut res_m: [i128; 96] = [0; 96];
+    let mut res_f: [i128; 96] = [0; 96];
+
+    res_m[0] = new_males;
+    res_f[0] = new_females;
+
+    let f_iter = f_pop.iter().enumerate();
+    let m_iter = m_pop.iter().enumerate();
+    for (i, count) in f_iter {
+        if i < 95{
+            res_f[i+1] = *count;
+        }
+    }
+    for (i, count) in m_iter {
+        if i < 95{
+            res_m[i+1] = *count;
+        }
+    }
+    return (res_m, res_f);
+}
+
+fn main() {
+
+    // this whole part is just for reading from stdin...
+
+    let mut input_m = String::new();
+    let mut input_f = String::new();
+    let mut input_n = String::new();
+
+    println!("Enter the number of male rabbits to start with:");
+    io::stdin().read_line(&mut input_m).expect("failed to read input");
+    println!("Enter the number of female rabbits to start with:");
+    io::stdin().read_line(&mut input_f).expect("failed to read input");
+    println!("Enter the number of rabbits you want to reach:");
+    io::stdin().read_line(&mut input_n).expect("failed to read input");
+
+    let trim_m = input_m.trim();
+    let trim_f = input_f.trim();
+    let trim_n = input_n.trim();
+
+    let trims = vec!(trim_m, trim_f, trim_n);
+    let mut mf: Vec<i128> = vec!(10, 10, 10000);
+    for (i, trim) in trims.iter().enumerate() {
+        let g = &trim.parse::<i128>().unwrap_or(20);
+        mf[i] = *g;
+    }
+
+    // . up until here
+
+    let (mut m, mut f, n_a) = init(mf[0], mf[1], mf[2]);
+    let mut sum_male: i128 = m.iter().sum();
+    let mut sum_female: i128 = f.iter().sum();
+    let mut sum = sum_male + sum_female;
+    // println!("There are now {} rabbits alive!", sum);
+    let mut i = 0;
+     while sum < n_a {
+        // this handling of tuples sucks, there's gotta be a better way...
+        let (r_m, r_f) = reproduce(m, f);
+        let (r_m, r_f) = age(m, f, r_m, r_f);
+        m = r_m;
+        f = r_f;
+        sum_male = m.iter().sum();
+        sum_female = f.iter().sum();
+        sum = sum_male + sum_female;
+        println!("There are now {} rabbits alive! {} males and {} females", sum, sum_male, sum_female);
+        thread::sleep(time::Duration::from_millis(500));
+        i += 1;
+    }
+     println!("It took {} months!", i);
+}