Submission #680405

#	Time	Username	Problem	Language	Result	Execution time	Memory
680405		bashkort	Crossing (JOI21_crossing)	C++17	100 / 100	742 ms	19404 KiB

Main

#include <bits/stdc++.h>

using namespace std;
using ll = long long;

string cross(string &a, string &b) {
    string res(a.size(), 'a');
    for (int i = 0; i < a.size(); ++i) {
        if (a[i] == b[i]) {
            res[i] = a[i];
        } else {
            res[i] = 'J' ^ 'O' ^ 'I' ^ a[i] ^ b[i];
        }
    }
    return res;
}

constexpr int MOD[]{1000'000'000 + 7, 228228227};
constexpr int P = 239, hsz = size(MOD);

struct Info {
    array<int, hsz> h{}, power{}, sum{};

    Info() = default;
};

vector<Info> t;
vector<int> tag;
int sz;

void apply(int x, int y) {
    if (y != -1) {
        for (int i = 0; i < hsz; ++i) {
            t[x].h[i] = 1LL * t[x].sum[i] * y % MOD[i];
        }
        tag[x] = y;
    }
}

void push(int x) {
    apply(x << 1, tag[x]);
    apply(x << 1 | 1, tag[x]);
    tag[x] = -1;
}

void pull(int x) {
    for (int i = 0; i < hsz; ++i) {
        t[x].h[i] = (t[x << 1].h[i] + 1LL * t[x << 1].power[i] * P % MOD[i] * t[x << 1 | 1].h[i]) % MOD[i];
        t[x].power[i] = 1LL * t[x << 1].power[i] * t[x << 1 | 1].power[i] % MOD[i] * P % MOD[i];
        t[x].sum[i] = (t[x << 1].sum[i] + 1LL * t[x << 1].power[i] * P % MOD[i] * t[x << 1 | 1].sum[i]) % MOD[i];
    }
}

int to_int(char c) {
    return c == 'J' ? 0 : 1 + (c == 'O');
}

void init(int n, string T) {
    sz = 1 << __lg(n) + bool(n & (n - 1));
    tag.assign(sz << 1, -1), t.resize(sz << 1);

    for (int i = 0; i < n; ++i) {
        for (int j = 0; j < hsz; ++j) {
            t[i + sz].sum[j] = t[i + sz].power[j] = 1;
            t[i + sz].h[j] = to_int(T[i]);
        }
    }
    for (int i = sz - 1; i > 0; --i) {
        pull(i);
    }
}

void rangeApply(int l, int r, int tg, int x = 1, int lx = 0, int rx = sz) {
    if (l >= rx || lx >= r) {
        return;
    }
    if (l <= lx && rx <= r) {
        apply(x, tg);
        return;
    }

    push(x);

    int mid = (lx + rx) >> 1;

    rangeApply(l, r, tg, x << 1, lx, mid), rangeApply(l, r, tg, x << 1 | 1, mid, rx);

    pull(x);
}

array<int, hsz> hashed(string &s) {
    array<int, hsz> ans{};
    for (int i = int(s.size()) - 1; i >= 0; --i) {
        for (int j = 0; j < hsz; ++j) {
            ans[j] = (1LL * ans[j] * P + to_int(s[i])) % MOD[j];
        }
    }
    return ans;
}

int main() {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);

    int n;
    cin >> n;

    string A, B, C;
    cin >> A >> B >> C;

    unordered_set<string> every{A, B, C};

    queue<string> qu;
    qu.push(A), qu.push(B), qu.push(C);

    while (!qu.empty()) {
        string s = qu.front();
        qu.pop();

        for (string to : every) {
            string res = cross(s, to);

            if (!every.count(res)) {
                qu.push(res);
                every.insert(res);
            }
        }
    }

    set<array<int, hsz>> st;
    for (string s : every) {
        st.insert(hashed(s));
    }

    int q;
    cin >> q;

    string T;
    cin >> T;

    init(n, T);

    cout << (st.count(t[1].h) ? "Yes\n" : "No\n");

    while (q--) {
        int l, r;
        char c;
        cin >> l >> r >> c;

        rangeApply(l - 1, r, to_int(c));

//        assert(t[1].h == hashed(T));
        cout << (st.count(t[1].h) ? "Yes\n" : "No\n");
    }

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'std::string cross(std::string&, std::string&)':
Main.cpp:8:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
    8 |     for (int i = 0; i < a.size(); ++i) {
      |                     ~~^~~~~~~~~~
Main.cpp: In function 'void init(int, std::string)':
Main.cpp:59:23: warning: suggest parentheses around '+' inside '<<' [-Wparentheses]
   59 |     sz = 1 << __lg(n) + bool(n & (n - 1));
      |               ~~~~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 23 / 23
• Subtask 3: 23 / 23
• Subtask 4: 51 / 51