add abc404c.rs

Author: rchaser53

src/abc/abc404c.rs

@@ -0,0 +1,57 @@
+/** THIS IS AN OUTPUT FILE. NOT EDIT THIS FILE DIRECTLY. **/
+use proconio::input;
+use proconio::marker::*;
+use std::marker::PhantomData;
+use std::cmp::*;
+use std::collections::*;
+use itertools::Itertools;
+
+
+fn main() {
+  input! {
+    n:usize,
+    m:usize,
+    ab:[(Usize1,Usize1);m]
+  }
+
+  if m != n {
+    println!("No");
+    return;
+  }
+
+  let mut g = vec![vec![];n];
+  for (a,b) in ab {
+    g[a].push(b);
+    g[b].push(a);
+  }
+
+  for i in 0..n {
+    if g[i].len() != 2 {
+      println!("No");
+      return;
+    }
+  }
+
+
+  let mut seen = vec![false;n];
+  let mut ci = 0;
+  let mut li = 10usize.pow(9);
+  while !seen[ci] {
+    seen[ci] = true;
+    for &ni in &g[ci] {
+      if li != ni {
+        li = ci;
+        ci = ni;
+        break;
+      }
+    }
+  }
+
+  for f in seen {
+    if !f {
+      println!("No");
+      return;
+    }
+  }
+  println!("Yes");
+}