Feeding people with fruit from dailyprogrammer 242 easy.

242easy.rs

use std::fmt;

struct Plant {
    age: u32,
}

struct Garden {
    plants: Vec<Plant>,
    fruit: u32,
}

impl Garden {
    fn new(n: u32) -> Garden {
        Garden {
            plants: Vec::new(),
            fruit: n,
        }
    }

    fn plant_fruit(&mut self) {
        for _ in 0..self.fruit {
            self.plants.push(Plant{ age: 0 });
        }
        self.fruit = 0
    }

    fn grow(&mut self) {
        for p in self.plants.iter_mut() {
            p.age += 1;
            self.fruit += p.age;
        }
    }
}

impl fmt::Debug for Garden {
    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
        let mut total = 0;
        for p in &self.plants {
            total += p.age + 1
        }

        write!(f, "Garden, fruit: {}, capacity: {}", self.fruit, total)
    }
}

fn main() {
    println!("Solution: {}", solve(15, 200));
    println!("Solution: {}", solve(1, 50000));
    println!("Solution: {}", solve(250, 150000));
}

fn solve(n: u32, goal: u32) -> u32 {
    let mut g = Garden::new(n);
    let mut iter = 1;
    while g.fruit < goal {
        g.plant_fruit();
        g.grow();
        iter += 1;
    }

    iter
}