less frequest cast with size

src/population.rs

@@ -15,6 +15,7 @@ pub struct Population {
     pub height: i32,
     pub age: i32,
     pub plague: Disease,
+    pub size: usize,
 }
 
 pub fn human_idx(x: i32, y: i32, width: i32) -> usize {
@@ -32,28 +33,30 @@ impl Population {
     ) -> Self {
         let mut rng = rand::thread_rng();
 
+        let size: usize = (width * height) as usize;
+
         let mut the_humans: Vec<Human> = vec![
             Human {
                 x: 0,
                 y: 0,
                 present_state: State::Normal
             };
-            (width * height) as usize
+            size
         ];
         for x in 0..width {
             for y in 0..height {
                 let idx = human_idx(x, y, width);
                 let mut present_state = State::Normal;
                 if (start_infected_ratio) > 0
-                    && (rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_infected_ratio as i32)
+                    && (rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_infected_ratio)
                 {
                     present_state = State::Infected;
-                } else if start_immune_ratio > 0
-                    && rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_immune_ratio as i32
+                } else if (start_immune_ratio > 0)
+                    && (rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_immune_ratio)
                 {
                     present_state = State::Immune;
-                } else if start_dead_ratio > 0
-                    && rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_dead_ratio as i32
+                } else if (start_dead_ratio > 0)
+                    && (rng.gen_range(0..CORRECTED_PERCENTAGE) <= start_dead_ratio)
                 {
                     present_state = State::Dead;
                 }
@@ -69,6 +72,7 @@ impl Population {
             plague: plague,
             age: 0,
             humans: the_humans,
+            size: size,
         }
     }
     // pub fn change_disease(&mut self, plague:Disease){
@@ -98,15 +102,15 @@ impl Population {
 
     pub fn propagate(&mut self) -> [i32; 4] {
         let mut people_to_check: Vec<Point> =
-            Vec::with_capacity((self.width * self.height) as usize);
+            Vec::with_capacity(self.size);
         let mut possible_infected: Vec<Point> =
-            Vec::with_capacity((self.width * self.height) as usize);
+            Vec::with_capacity(self.size);
         let mut people_to_infect: Vec<Point> =
-            Vec::with_capacity((self.width * self.height) as usize);
+            Vec::with_capacity(self.size);
         let mut people_to_cure: Vec<Point> =
-            Vec::with_capacity((self.width * self.height) as usize);
+            Vec::with_capacity(self.size);
         let mut people_to_kill: Vec<Point> =
-            Vec::with_capacity((self.width * self.height) as usize);
+            Vec::with_capacity(self.size);
         let mut stats: [i32; 4] = [0, 0, 0, 0];
         // stats[0] Normal stats[1] Infected stats[2] Immune stats[3] Dead
 
@@ -233,7 +237,7 @@ impl Population {
         }
         assert_eq!(
             stats[0] + stats[1] + stats[2] + stats[3],
-            self.humans.len() as i32
+            self.size as i32
         );
         stats
     }