Submission #1200512

#	Time	Username	Problem	Language	Result	Execution time	Memory
1200512		tfgs	Round words (IZhO13_rowords)	C++17	100 / 100	75 ms	43452 KiB

rowords

#ifndef LOCAL
#include <bits/stdc++.h>
#endif
using namespace std;
#pragma GCC optimize("Ofast,unroll-loops,no-stack-protector")
#pragma GCC target("avx2")

#define int int64_t
const int inf=1e18;

#ifdef LOCAL
#include "algo/debug.h"
#else
template <typename... Args>
void dummy(Args&&... args){}
#define ps dummy
#endif

#define f first
#define s second
template<class T> using V = vector<T>; 
using vi = V<int>;
using vb = V<bool>;
using vs = V<string>;

#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x) 
#define len(x) (int)((x).size())
#define rsz resize
#define ins insert
#define ft front()
#define bk back()
#define pb push_back
#define eb emplace_back
#define pf push_front
#define lb lower_bound
#define ub upper_bound
#define ai2 array<int,2>
#define ai3 array<int,3>
#define ai4 array<int,4>
#define ai5 array<int,5>
template<class T> int lwb(const V<T>& a, const T& b) { return lb(all(a),b)-begin(a); }
template<class T> int upb(const V<T>& a, const T& b) { return ub(all(a),b)-begin(a); }
template<class T> bool ckmin(T& a, const T& b) { return a > b ? a=b, true : false; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a=b, true : false; }
#define pct __builtin_popcountll
#define ctz __builtin_ctzll
#define clz __builtin_clzll
constexpr int p2(int x) { return (int)1 << x; }
constexpr int msk2(int x) { return (int)(1 << x) - 1; }
constexpr int bits(int x) { return x == 0 ? 0 : 63-clz(x); } // floor(log2(x)) 
template<class T>void UNIQUE(V<T>& v) { sort(all(v)); v.erase(unique(all(v)),end(v)); }
template<class T, class Cmp>void UNIQUE(V<T>& v, Cmp cmp) { sort(all(v), cmp); v.erase(unique(all(v)),end(v)); }
template<class T,class U>void erase(T& t, const U& u) { auto it = t.find(u); assert(it != end(t)); t.erase(it); }
template<class F> struct y_combinator_result {
    F f;
    template<class T> explicit y_combinator_result(T &&f): f(std::forward<T>(f)) {}
    template<class ...Args> decltype(auto) operator()(Args &&...args) { return f(std::ref(*this), std::forward<Args>(args)...); }
};
template<class Fun> decltype(auto) yy(Fun &&fun) { return y_combinator_result<std::decay_t<Fun>>(std::forward<Fun>(fun)); }


struct Bit {
    int n;
    vi a;
    Bit(int n) : n(n + 1), a(n + 1) {}
    void point_add(int i, int x) {
        i++;
        for (; i < n; i += i & -i) {
            a[i] += x;
        }
    }
    int prefix_sum(int r) {
        int res = 0;
        for (; r > 0; r -= r & -r) {
            res += a[r]; 
        }
        return res;
    }
};

void solve() {
    string s, t; cin >> s >> t;
    t = t + t;
    int n = len(s); 
    int m = len(t);


    int ans = 0;

    auto work = [&]() {
        vector i_h(n + 1, vi(m + 1));
        auto i_v = i_h;
        for (int j = 0; j <= m; j++) i_h[0][j] = j;

        for (int i = 1; i <= n; i++) {
            for (int j = 1; j <= m; j++) {
                if (s[i - 1] == t[j - 1]) {
                    i_h[i][j] = i_v[i][j - 1];
                    i_v[i][j] = i_h[i - 1][j];
                } else {
                    i_h[i][j] = max(i_v[i][j - 1], i_h[i - 1][j]);
                    i_v[i][j] = min(i_v[i][j - 1], i_h[i - 1][j]);
                }
            }
        }

        Bit i_h_vals(m / 2 + 1);
        for (int i = 1; i <= m / 2; i++) {
            i_h_vals.point_add(i_h[n][i], 1);
        }
        for (int i = 1; i <= m / 2; i++) {
            ckmax(ans, i_h_vals.prefix_sum(i));
            i_h_vals.point_add(i_h[n][i], -1);
            i_h_vals.point_add(i_h[n][i + m / 2], 1);
        }
    };
    work();
    reverse(all(t));
    work();

    cout << ans << '\n';
}

signed main() {
    ios::sync_with_stdio(false);
    cin.tie(0); cout.tie(0);
    solve();
    return 0;
}

• Subtask 1: 100 / 100