Add yukicoder/2616.rs yukicoder/2619.rs

yukicoder/2616.rs

@@ -0,0 +1,203 @@
+// 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"));
+}
+
+// Segment Tree. This data structure is useful for fast folding on intervals of an array
+// whose elements are elements of monoid I. Note that constructing this tree requires the identity
+// element of I and the operation of I.
+// Verified by: yukicoder No. 2220 (https://yukicoder.me/submissions/841554)
+struct SegTree<I, BiOp> {
+    n: usize,
+    orign: usize,
+    dat: Vec<I>,
+    op: BiOp,
+    e: I,
+}
+
+impl<I, BiOp> SegTree<I, BiOp>
+    where BiOp: Fn(I, I) -> I,
+          I: Copy {
+    pub fn new(n_: usize, op: BiOp, e: I) -> Self {
+        let mut n = 1;
+        while n < n_ { n *= 2; } // n is a power of 2
+        SegTree {n: n, orign: n_, dat: vec![e; 2 * n - 1], op: op, e: e}
+    }
+    // ary[k] <- v
+    pub fn update(&mut self, idx: usize, v: I) {
+        debug_assert!(idx < self.orign);
+        let mut k = idx + self.n - 1;
+        self.dat[k] = v;
+        while k > 0 {
+            k = (k - 1) / 2;
+            self.dat[k] = (self.op)(self.dat[2 * k + 1], self.dat[2 * k + 2]);
+        }
+    }
+    // [a, b) (half-inclusive)
+    // http://proc-cpuinfo.fixstars.com/2017/07/optimize-segment-tree/
+    #[allow(unused)]
+    pub fn query(&self, rng: std::ops::Range<usize>) -> I {
+        let (mut a, mut b) = (rng.start, rng.end);
+        debug_assert!(a <= b);
+        debug_assert!(b <= self.orign);
+        let mut left = self.e;
+        let mut right = self.e;
+        a += self.n - 1;
+        b += self.n - 1;
+        while a < b {
+            if (a & 1) == 0 {
+                left = (self.op)(left, self.dat[a]);
+            }
+            if (b & 1) == 0 {
+                right = (self.op)(self.dat[b - 1], right);
+            }
+            a = a / 2;
+            b = (b - 1) / 2;
+        }
+        (self.op)(left, right)
+    }
+}
+
+/// Verified by https://atcoder.jp/contests/abc198/submissions/21774342
+mod mod_int {
+    use std::ops::*;
+    pub trait Mod: Copy { fn m() -> i64; }
+    #[derive(Copy, Clone, Hash, PartialEq, Eq, PartialOrd, Ord)]
+    pub struct ModInt<M> { pub x: i64, phantom: ::std::marker::PhantomData<M> }
+    impl<M: Mod> ModInt<M> {
+        // x >= 0
+        pub fn new(x: i64) -> Self { ModInt::new_internal(x % M::m()) }
+        fn new_internal(x: i64) -> Self {
+            ModInt { x: x, phantom: ::std::marker::PhantomData }
+        }
+        pub fn pow(self, mut e: i64) -> Self {
+            debug_assert!(e >= 0);
+            let mut sum = ModInt::new_internal(1);
+            let mut cur = self;
+            while e > 0 {
+                if e % 2 != 0 { sum *= cur; }
+                cur *= cur;
+                e /= 2;
+            }
+            sum
+        }
+        #[allow(dead_code)]
+        pub fn inv(self) -> Self { self.pow(M::m() - 2) }
+    }
+    impl<M: Mod> Default for ModInt<M> {
+        fn default() -> Self { Self::new_internal(0) }
+    }
+    impl<M: Mod, T: Into<ModInt<M>>> Add<T> for ModInt<M> {
+        type Output = Self;
+        fn add(self, other: T) -> Self {
+            let other = other.into();
+            let mut sum = self.x + other.x;
+            if sum >= M::m() { sum -= M::m(); }
+            ModInt::new_internal(sum)
+        }
+    }
+    impl<M: Mod, T: Into<ModInt<M>>> Sub<T> for ModInt<M> {
+        type Output = Self;
+        fn sub(self, other: T) -> Self {
+            let other = other.into();
+            let mut sum = self.x - other.x;
+            if sum < 0 { sum += M::m(); }
+            ModInt::new_internal(sum)
+        }
+    }
+    impl<M: Mod, T: Into<ModInt<M>>> Mul<T> for ModInt<M> {
+        type Output = Self;
+        fn mul(self, other: T) -> Self { ModInt::new(self.x * other.into().x % M::m()) }
+    }
+    impl<M: Mod, T: Into<ModInt<M>>> AddAssign<T> for ModInt<M> {
+        fn add_assign(&mut self, other: T) { *self = *self + other; }
+    }
+    impl<M: Mod, T: Into<ModInt<M>>> SubAssign<T> for ModInt<M> {
+        fn sub_assign(&mut self, other: T) { *self = *self - other; }
+    }
+    impl<M: Mod, T: Into<ModInt<M>>> MulAssign<T> for ModInt<M> {
+        fn mul_assign(&mut self, other: T) { *self = *self * other; }
+    }
+    impl<M: Mod> Neg for ModInt<M> {
+        type Output = Self;
+        fn neg(self) -> Self { ModInt::new(0) - self }
+    }
+    impl<M> ::std::fmt::Display for ModInt<M> {
+        fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+            self.x.fmt(f)
+        }
+    }
+    impl<M: Mod> From<i64> for ModInt<M> {
+        fn from(x: i64) -> Self { Self::new(x) }
+    }
+} // mod mod_int
+
+macro_rules! define_mod {
+    ($struct_name: ident, $modulo: expr) => {
+        #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+        pub struct $struct_name {}
+        impl mod_int::Mod for $struct_name { fn m() -> i64 { $modulo } }
+    }
+}
+const MOD: i64 = 998_244_353;
+define_mod!(P, MOD);
+type MInt = mod_int::ModInt<P>;
+
+// Depends on MInt.rs
+fn fact_init(w: usize) -> (Vec<MInt>, Vec<MInt>) {
+    let mut fac = vec![MInt::new(1); w];
+    let mut invfac = vec![0.into(); w];
+    for i in 1..w {
+        fac[i] = fac[i - 1] * i as i64;
+    }
+    invfac[w - 1] = fac[w - 1].inv();
+    for i in (0..w - 1).rev() {
+        invfac[i] = invfac[i + 1] * (i as i64 + 1);
+    }
+    (fac, invfac)
+}
+
+fn main() {
+    input! {
+        n: usize,
+        p: [usize; n],
+    }
+    let (fac, invfac) = fact_init(n + 1);
+    let mut st = SegTree::new(n, |x, y| x + y, 0);
+    let mut ans = MInt::new(0);
+    for i in 0..n {
+        let a = st.query(0..p[i] - 1);
+        let b = i - a;
+        let c = p[i] - 1 - a;
+        let d = n - 1 - i - c;
+        ans += fac[a + d] * invfac[a] * invfac[d] * fac[b + c] * invfac[b] * invfac[c];
+        st.update(p[i] - 1, 1);
+    }
+    println!("{}", ans);
+}

yukicoder/2619.rs

@@ -0,0 +1,43 @@
+// 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: staircase-nim
+fn main() {
+    input! {
+        n: usize,
+        x: [i64; n],
+    }
+    let mut g = 0;
+    for i in 0..(n + 1) / 2 {
+        g ^= x[n - 2 * i - 1] - if 2 * i + 2 > n { 0 } else { x[n - 2 * i - 2] };
+    }
+    println!("{}", if g == 0 { "Second" } else { "First" });
+}