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use std::fmt;
use std::io::{self, BufRead};
use std::time::Instant;
struct Graph {
size: usize,
matrix: Vec<Vec<u8>>,
}
impl Clone for Graph {
fn clone(&self) -> Self {
let mut matrix = vec![vec![0; self.size]; self.size];
for row in 0..self.size {
for col in 0..self.size {
matrix[row][col] = self.matrix[row][col];
}
}
return Graph {
size: self.size,
matrix,
};
}
}
impl fmt::Display for Graph {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
for row in 0..self.size {
for col in 0..self.size {
write!(f, "{}", self.matrix[row][col])?;
if col < self.size - 1 {
write!(f, " ")?;
}
}
if row < self.size - 1 {
write!(f, "\n")?;
}
}
return Ok(());
}
}
impl Graph {
fn from_g6(line: &String) -> Graph {
let mut chars: Vec<u8> = Vec::new();
for character in line.chars() {
chars.push((character as i32 - 63) as u8);
}
// TODO: spec allows multi-byte vector size
let size = chars[0] as usize;
let bytes = &chars[1..];
let mut matrix: Vec<Vec<u8>> = vec![vec![0; size]; size];
let mut i = 0;
for col in 1..size {
for row in 0..col {
let bit: u8 = bytes[i / 6] >> (5 - i % 6) & 1;
matrix[row][col] = bit;
matrix[col][row] = bit;
i += 1;
}
}
return Graph { size, matrix };
}
fn degree(&self, vertex: usize) -> usize {
let mut sum: usize = 0;
for i in &self.matrix[vertex] {
sum += *i as usize;
}
return sum;
}
fn get_closure(&self) -> Graph {
let mut closure = self.clone();
for _ in 0..(closure.size * closure.size) {
for row in 0..closure.size {
for col in 0..closure.size {
if row == col {
continue;
}
let sum = closure.degree(row) + closure.degree(col);
if sum >= closure.size {
closure.matrix[row][col] = 1;
}
}
}
}
return closure;
}
fn is_complete(&self) -> bool {
for row in 0..self.size {
for col in 0..self.size {
if row != col && self.matrix[row][col] != 1 {
return false;
}
}
}
return true;
}
}
fn main() {
let stdin = io::stdin();
let mut t = 0;
let mut count = 0;
for line in stdin.lock().lines() {
let line = line.unwrap();
let start = Instant::now();
let g = Graph::from_g6(&line);
let closure = g.get_closure();
if closure.is_complete() {
count += 1;
}
let elapsed = start.elapsed();
t += elapsed.as_nanos();
}
println!("Time elapsed: {}s", t as f64 / 1e9);
println!("Count of Hamiltonian graphs: {}", count);
}
|
