Add atcoder/abc341/g.rs

atcoder/abc341/g.rs

@@ -0,0 +1,65 @@
+use std::io::{Write, BufWriter};
+// https://qiita.com/tanakh/items/0ba42c7ca36cd29d0ac8
+macro_rules! input {
+    ($($r:tt)*) => {
+        let stdin = std::io::stdin();
+        let mut bytes = std::io::Read::bytes(std::io::BufReader::new(stdin.lock()));
+        let mut next = move || -> String{
+            bytes.by_ref().map(|r|r.unwrap() as char)
+                .skip_while(|c|c.is_whitespace())
+                .take_while(|c|!c.is_whitespace())
+                .collect()
+        };
+        input_inner!{next, $($r)*}
+    };
+}
+
+macro_rules! input_inner {
+    ($next:expr) => {};
+    ($next:expr,) => {};
+    ($next:expr, $var:ident : $t:tt $($r:tt)*) => {
+        let $var = read_value!($next, $t);
+        input_inner!{$next $($r)*}
+    };
+}
+
+macro_rules! read_value {
+    ($next:expr, [ $t:tt ; $len:expr ]) => {
+        (0..$len).map(|_| read_value!($next, $t)).collect::<Vec<_>>()
+    };
+    ($next:expr, $t:ty) => ($next().parse::<$t>().expect("Parse error"));
+}
+
+// Tags: convex-hull
+fn main() {
+    let out = std::io::stdout();
+    let mut out = BufWriter::new(out.lock());
+    macro_rules! puts {($($format:tt)*) => (let _ = write!(out,$($format)*););}
+    input! {
+        n: usize,
+        a: [i64; n],
+    }
+    let mut acc = vec![0; n + 1];
+    for i in 0..n {
+        acc[i + 1] = acc[i] + a[i];
+    }
+    let mut st = vec![(n as i64, acc[n])];
+    let mut dp = vec![0.0; n];
+    for i in (0..n).rev() {
+        let (x, y) = (i as i64, acc[i]);
+        while st.len() >= 2 {
+            let (x2, y2) = st[st.len() - 1];
+            let (x1, y1) = st[st.len() - 2];
+            if (y2 - y1) * (x1 - x) > (y1 - y) * (x2 - x1) {
+                break;
+            }
+            st.pop();
+        }
+        let (x2, y2) = st[st.len() - 1];
+        dp[i] = (y2 - y) as f64 / (x2 - x) as f64;
+        st.push((x, y));
+    }
+    for i in 0..n {
+        puts!("{}\n", dp[i]);
+    }
+}