Module c
Expand description
ยงABC 393 C -
refs: https://atcoder.jp/contests/abc393/tasks/abc393_c
use std::collections::HashSet;
use proconio::input;
fn swap(edge: (usize, usize)) -> (usize, usize) {
if edge.0 < edge.1 {
edge
} else {
(edge.1, edge.0)
}
}
fn main() {
input! {
_: usize, m: usize,
edges: [(usize, usize); m]
}
let mut set = HashSet::new();
let mut ans = 0;
for e in edges {
if e.0 == e.1 {
ans += 1;
continue;
}
let e = swap(e);
if set.contains(&e) {
ans += 1;
} else {
set.insert(e);
}
}
println!("{ans}");
}