Reddit Programming Challenge 266

bonus.rs

fn bonus (input: &String) {
    // input is the same as in the main.rs
    let mut adj_mat:Vec<usize> = Vec::new();
    let mut length = 0;
    for line in input.split('\n') {
        let connections: Vec<_> = line.split_whitespace().collect();
        let conn_to:usize = parse_int(connections[0].to_string());
        // Tabs from input not handled...
        if conn_to <= 0 {
            continue;
        } else if connections.len() < 2 {
            // First line used to create a vector of size length*length
            length = conn_to;
            for _ in 0..length*length { 
                adj_mat.push(0)
            };
            continue;
        }
        let conn_to = parse_int(connections[1].to_string());
        
        let ij = (conn_from -1) * length + (conn_to - 1);
        let ji = (conn_to -1) * length + (conn_from - 1);
        if ij < adj_mat.len() {
            adj_mat[ij] += 1;
        }
        if ji < adj_mat.len() {
            adj_mat[ji] += 1;
        }
    }
    for i in 0..adj_mat.len() {   
        print!("{} ", adj_mat[i]);
        if (i +1)%length == 0 {
            println!("");
        }
    }
}

main.rs

// char to int parsing method
fn parse_int(str: String) -> usize {
    str.chars().fold(0, |val, c|  (val*10 + (c.to_digit(10).unwrap()) as usize))
}

// Read input, build an array of connections and prints it
fn build_edges(input: &String) {
    let mut edges:Vec<usize> = Vec::new();

    for line in input.split('\n') {
        for connection in line.split(' ') {
            let index = parse_int(connection.to_string());
            if index >= edges.len() {
                edges.push(1);
            } else {
                edges[index] += 1;
            }
        } 
    }
    
    for i in 1..edges.len() {
        println!("Node {} has a degree of {}", i, edges[i]);
    }
}

fn main() {
    let input:String = "16
1 2
1 3
2 3
1 4
3 4
1 5
2 5
1 6
2 6
3 6
3 7
5 7
6 7
3 8
4 8
6 8
7 8
2 9
5 9
6 9
2 10
9 10
6 11
7 11
8 11
9 11
10 11
1 12
6 12
7 12
8 12
11 12
6 13
7 13
9 13
10 13
11 13
5 14
8 14
12 14
13 14
1 15
2 15
5 15
9 15
10 15
11 15
12 15
13 15
1 16
2 16
5 16
6 16
11 16
12 16
13 16
14 16
15 16".to_string();

    build_edges(&input);
}