projecteuler.net/028/main.rs

fn get_matrix(n: usize) -> u32 {
    let mut xss: Vec<Vec<u32>> = Vec::new();
    for _i in 0..n {
        let mut r = Vec::new();
        for _j in 0..n {
            r.push(0u32);
        }
        xss.push(r);
    }

    xss[n/2][n/2] = 1;

    let mvs = [(1, 0), (0, -1), (-1, 0), (0, 1)];
    let mut mvi = 0usize;
    let mut l = 1;
    let mut li = 0;
    let mut i: usize = n / 2;
    let mut j: usize = n / 2 + 1;
    let mut res = 1;
    for k in 2u32..= (n * n) as u32 {
        xss[i][j] = k;
        let mv = mvs[mvi];
        //println!("mvi: {}", mvi);
        if mv.0 == 1 { i += 1; }
        if mv.0 == -1 { i -= 1; }
        if mv.1 == 1 { j += 1; }
        if mv.1 == -1 { j-= 1; }
        li += 1;
        //println!("li vs l: {} vs {}", li, l);
        if li == l {
            mvi += 1;
            li = 0;
            if mvi == 1 { l += 1; }
            if mvi == 3 { l += 1; }
            if mvi == 4 { mvi = 0; }
            let d = if mvi == 0 { k } else { k + 1 };
            //println!("{}", d);
            res += d;
        }
    }

    //for i in 0..n {
    //    for j in 0..n {
    //        print!("{}\t", xss[i][j]);
    //    }
    //    println!("");
    //}

    res
}

fn main() {
    println!("{}", get_matrix(1001));
}