Add yukicoder/2761.rs yukicoder/2763.rs

yukicoder/2761.rs

@@ -0,0 +1,159 @@
+use std::io::Read;
+
+fn get_word() -> String {
+    let stdin = std::io::stdin();
+    let mut stdin=stdin.lock();
+    let mut u8b: [u8; 1] = [0];
+    loop {
+        let mut buf: Vec<u8> = Vec::with_capacity(16);
+        loop {
+            let res = stdin.read(&mut u8b);
+            if res.unwrap_or(0) == 0 || u8b[0] <= b' ' {
+                break;
+            } else {
+                buf.push(u8b[0]);
+            }
+        }
+        if buf.len() >= 1 {
+            let ret = String::from_utf8(buf).unwrap();
+            return ret;
+        }
+    }
+}
+
+fn get<T: std::str::FromStr>() -> T { get_word().parse().ok().unwrap() }
+
+// 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)
+#[derive(Clone)]
+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)
+    }
+}
+
+struct Rng {
+    x: u64,
+}
+
+impl Rng {
+    fn new() -> Self {
+        use std::hash::{Hasher, BuildHasher};
+        let hm = std::collections::HashMap::<i32, i32>::new();
+        let mut hash = hm.hasher().build_hasher();
+        hash.write_u32(8128);
+        Rng {
+            x: hash.finish(),
+        }
+    }
+    fn next(&mut self) -> u32 {
+        let a = 0xdead_c0de_0013_3331u64;
+        let b = 2457;
+        self.x = self.x.wrapping_mul(a).wrapping_add(b);
+        let x = self.x;
+        ((x ^ x << 10) >> 32) as _
+    }
+}
+
+// https://yukicoder.me/problems/no/2761 (3)
+// 文字列の位置が固定 (シフトしない) であるため、特にローリングハッシュである必要はなく、位置ごとに乱数を生成すれば良い。
+// また ModInt である必要もないので xor で演算している (zobrist hash と同様)。これで解説より定数倍高速である。
+fn main() {
+    let mut rng = Rng::new();
+    let n: usize = get();
+    let l: usize = get();
+    let q: usize = get();
+    let mut s = vec![];
+    for _ in 0..n {
+        s.push(get_word().bytes().collect::<Vec<_>>());
+    }
+    let mut val = vec![[0u64; 26]; l];
+    for i in 0..l {
+        for j in 0..26 {
+            val[i][j] = rng.next() as u64;
+            val[i][j] |= (rng.next() as u64) << 32;
+        }
+    }
+    let mut st = vec![SegTree::new(l, |x, y| x ^ y, 0); n];
+    for i in 0..n {
+        for j in 0..l {
+            let idx = (s[i][j] - b'a') as usize;
+            st[i].update(j, val[j][idx]);
+        }
+    }
+    for _ in 0..q {
+        let ty: i32 = get();
+        if ty == 1 {
+            let k = get::<usize>() - 1;
+            let c: char = get();
+            let d: char = get();
+            let v = val[k][(d as u8 - b'a') as usize];
+            for i in 0..n {
+                if s[i][k] == c as u8 {
+                    s[i][k] = d as u8;
+                    st[i].update(k, v);
+                }
+            }
+        } else {
+            let mut sum = 0;
+            let t = get_word().bytes().collect::<Vec<_>>();
+            for i in 0..t.len() {
+                sum ^= val[i][(t[i] - b'a') as usize];
+            }
+            let mut ans = 0;
+            for i in 0..n {
+                if st[i].query(0..t.len()) == sum {
+                    ans += 1;
+                }
+            }
+            println!("{}", ans);
+        }
+    }
+}