From 99c64ad172279e8fe15db920c1e9321246e25a1d Mon Sep 17 00:00:00 2001
From: "Dr. Matthias Ratajczak" <m.ratajczak@hzdr.de>
Date: Tue, 27 Jun 2023 17:41:58 +0200
Subject: [PATCH] finish 94

---
 src/euler94/Cargo.toml  |  6 +++++
 src/euler94/src/main.rs | 51 ++++++++++++++++++++++++++---------------
 2 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/src/euler94/Cargo.toml b/src/euler94/Cargo.toml
index e197630..0f099c5 100644
--- a/src/euler94/Cargo.toml
+++ b/src/euler94/Cargo.toml
@@ -6,3 +6,9 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+f128 = "0.2.9"
+num-traits = "0.2.15"
+
+[profile.release]
+lto = "fat"
+codegen-units = 1
diff --git a/src/euler94/src/main.rs b/src/euler94/src/main.rs
index 127fa08..527b02f 100644
--- a/src/euler94/src/main.rs
+++ b/src/euler94/src/main.rs
@@ -1,50 +1,65 @@
-type Num = u64;
+use f128::f128;
+use num_traits::Float;
 
-const ONE_BILLION: Num = 1_000_000_000;
+type Num = f128;
+
+static mut ONE_BILLION: Num = f128::ZERO;
+const ONE: Num = f128::ONE;
 
 fn main() {
-    let mut sum = 0 as Num;
+    unsafe {
+        ONE_BILLION = f128::from(1_000_000_000.);
+    }
+
+    let mut sum = f128::ZERO;
+
     'outer: for i in 2.. {
-        let a_b = i as Num;
-        for c in [a_b - 1, a_b + 1] {
-            let t = Triangle::new(a_b, c);
+        let a = f128::from(i);
+
+        for c in [a - ONE, a + ONE] {
+            let t = Triangle::new(a, c);
             let p = t.perimeter();
 
-            if p > ONE_BILLION {
+            if unsafe { p > ONE_BILLION } {
                 break 'outer;
             }
 
             if t.has_integer_area() {
+                println!("{:.10}, {:.10}", t.a, t.c);
                 sum += p;
             }
         }
     }
 
-    println!("{sum}");
+    println!("{sum:.15}");
 }
 
 struct Triangle {
-    a_b: Num,
+    a: Num,
     c: Num,
 }
 
 impl Triangle {
-    fn new(a_b: Num, c: Num) -> Self {
-        Self { a_b, c }
+    fn new(a: Num, c: Num) -> Self {
+        Self { a, c }
     }
 
     fn perimeter(&self) -> Num {
-        2 * self.a_b + self.c
+        Num::TWO * self.a + self.c
     }
 
     fn has_integer_area(&self) -> bool {
-        let a_b = self.a_b as f64;
-        let c = self.c as f64;
-        let area = c / 4. * (4. * a_b.powi(2) - c.powi(2)).sqrt();
-        is_integer(area)
+        is_integer(self.area())
+    }
+
+    fn area(&self) -> Num {
+        let a = self.a;
+        let c = self.c;
+
+        c / Num::from(4.) * (Num::from(4.) * a.powi(2) - c.powi(2)).sqrt()
     }
 }
 
-fn is_integer(x: f64) -> bool {
-    (x.round() - x).abs() <= f64::EPSILON
+fn is_integer(x: Num) -> bool {
+    (x.round() - x).abs() <= Num::EPSILON
 }