Submission #1052223

#	Time	Username	Problem	Language	Result	Execution time	Memory
1052223		crafticat	Crossing (JOI21_crossing)	C++17	100 / 100	833 ms	41508 KiB

Main

#include <bits/stdc++.h>

using namespace std;

#include <bits/stdc++.h>

#include <utility>
using namespace std;

using ll = long long;
using pi = pair<int,int>;
using pl = pair<ll,ll>;

#define temp(T) template<class T>
temp(T) using V = vector<T>;
using vi = V<int>;
using vl = V<ll>;
using vvi = V<vi>;
using vpi = V<pi>;
using vb = V<bool>;
using vvb = V<vb>;
vi dx = {0,1,-1,0};
vi dy = {1,0,0,-1};

#define sz(x) x.size()
#define all(x) begin(x), end(x)
#define rall(x) rbegin(x), rend(x)
#define sor(x) sort(all(x))
#define rsz resize
#define ins insert
#define pb push_back
#define eb emplace_back
#define f first
#define s second

#define lb lower_bound
#define ub upper_bound

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define rep(a) F0R(_,a)
#define each(a,x) for (auto& a: x)

using str = string;

const int MOD = 1e9 + 7;
const ll BIG = 1e18;
const int INF = 1e9 + 2;

temp(T) bool ckmin(T& a, const T& b) {
    return b < a ? a = b, 1 : 0; } // set a = min(a,b)
temp(T) bool ckmax(T& a, const T& b) {
    return a < b ? a = b, 1 : 0; } // set a = max(a,b)

void unsyncIO() { cin.tie(0)->sync_with_stdio(0); }
// FILE I/O
void setIn(str s) { freopen(s.c_str(),"r",stdin); }
void setOut(str s) { freopen(s.c_str(),"w",stdout); }
void setIO(str s = "") {
    unsyncIO();
    if (sz(s)) setIn(s+".in"), setOut(s+".out"); // for USACO
}

#define read(x) int x; cin >> x

temp(T) void pr(T x) {
    cout << to_string(x);
}
temp(T) void prln(T x) {
    cout << to_string(x) << "\n";
}


vi readV(int n) {

    vi input(n);
    F0R(i,n)
        cin >> input[i];
    return input;
}

int rand(int a, int b) {
    return a + rand() % (b - a + 1);
}

#define gen(x,a,b) int x = rand(a,b)

temp(T) void moveAll(V<T> &a, V<T> &b) {
    each(x,b) {
        a.pb(x);
    }
    b.clear();
}

vi genArr(int n, int a, int b) {
    vi generated(n);
    F0R(i,n) {
        generated[i] = rand(a,b);
    }
    return generated;
}

vvi genTree(int n) {
    vvi g(n + 1);
    F0R(i,n) {
        gen(p,0,i);
        g[p].pb(i + 1);
        g[i + 1].pb(p);
    }

    return g;
}

vvb readGrid(int a, int b) {
    vvb grid(a + 2, vb(b + 2, true));

    F0R(i, a) {
        F0R(j, b) {
            bool k; cin >> k;
            grid[i + 1][j + 1] = k;
        }
    }
    return grid;
}

struct mint {
    ll v;

    mint(ll t) : v(t % MOD) {}
    mint() = default;
    mint operator*(mint other) {
        return {v * other.v};
    }
    void operator*=(mint other) {
        v *= other.v;
        v %= MOD;
    }
    mint operator+(mint other) {
        return {v + other.v};
    }
    void operator+=(mint other) {
        v += other.v;
        v %= MOD;
    }
};

V<V<mint>> prePrefix;
V<V<mint>> prePrefix2;

// TODO precompute
mint pow(mint a, int b) {
    if (b == 0) return 1;
    mint ans = pow(a, b / 2);
    ans = ans * ans;
    if (b % 2) ans *= a;
    return ans;
}

int v(char k) {
    if (k == 'O') return 0;
    if (k == 'I') return 1;
    if (k == 'J') return 2;
    exit(5);
}

struct Seg {
    Seg *left = nullptr, *right = nullptr;
    int l, r, mid;
    mint hash = 0;
    mint hash2 = 0;
    int lazy = -1;

    Seg(int l, int r, str &def) : l(l) ,r(r), mid((r + l) / 2) {
        if (r -l > 1) {
            left = new Seg(l,mid,def);
            right = new Seg(mid,r,def);
            hash = left->hash + right->hash * pow(mint(3), mid - l);
            hash2 = left->hash2 + right->hash2 * pow(mint(4), mid - l);
        } else {
            hash = v(def[l]);
            hash2 = v(def[l]);
        }
    }

    void push() {
        if (lazy != -1) {
            hash = prePrefix[lazy][r - l];
            hash2 = prePrefix2[lazy][r - l];
            if (r - l > 1) {
                left->lazy = lazy;
                right->lazy = lazy;
            }
            lazy = -1;
        }
    }

    void update(int a, int b, int k) {
        push();
        if (b <= l || a >= r) return;
        if (a <= l && b >= r) {
            lazy = k;
            push();
            return;
        }

        left->update(a,b,k);
        right->update(a,b,k);
        hash = left->hash + right->hash * pow(mint(3), mid - l);
        hash2 = left->hash2 + right->hash2 * pow(mint(4), mid - l);
    }
};

using has = pair<mint,mint>;

has findHash(str a) {
    mint h = 0;
    mint h2 = 0;
    mint power = 1;
    mint power2 = 1;
    F0R(i, sz(a)) {
        h += power * v(a[i]);
        h2 += power2 * v(a[i]);
        power *= 3;
        power2 *= 4;
    }
    return {h, h2};
}

str add(str a, str b) {
    str c = a;
    F0R(i, sz(a)) {
        if (a[i] == b[i]) continue;
        if ('O' != a[i] and 'O' != b[i]) c[i] = 'O';
        if ('J' != a[i] and 'J' != b[i]) c[i] = 'J';
        if ('I' != a[i] and 'I' != b[i]) c[i] = 'I';
    }
    return c;
}

V<has> hashes;
void genHashes(str a, str b, str c) {
    set<str> found;

    str acc = a;
    while (!found.count(acc)) {
        found.ins(acc);
        acc = add(acc,a);
        hashes.pb(findHash(acc));
        acc = add(acc,b);
        hashes.pb(findHash(acc));
        acc = add(acc,c);
        hashes.pb(findHash(acc));
    }
}

bool findMatch(has hash) {
    each(x, hashes) {
        if (x.f.v ==hash.f.v && x.s.v == hash.s.v) return true;
    }
    return false;
}

int main() {
    setIO();

    int n; cin >> n;
    V<str> starts(3);

    F0R(i, 3) {
        cin >> starts[i];
    }

    int q; cin >> q;
    string def; cin >> def;
    Seg seg(0, sz(def), def);

    vi perm = {0,1,2};
    do {
        genHashes(starts[perm[0]], starts[perm[1]], starts[perm[2]]);
    } while (next_permutation(all(perm)));

    prePrefix.rsz(3, V<mint>(n + 1));
    prePrefix2.rsz(3, V<mint>(n + 1));
    F0R(i, 3) {
        mint h = 0;
        mint h2 = 0;
        mint power = 1;
        mint power2 = 1;
        F0R(j, n + 1) {
            prePrefix[i][j] = h;
            prePrefix2[i][j] = h2;
            h += power * (i);
            h2 += power2 * (i);
            power *= 3;
            power2 *= 4;
        }
    }

    cout << ((findMatch({seg.hash,seg.hash2})) ? "Yes" : "No") << "\n";
    F0R(i, q) {
        int l, r; cin >> l >> r;
        l--;
        char c; cin >> c;

        seg.update(l, r, v(c));
        cout << ((findMatch({seg.hash,seg.hash2})) ? "Yes" : "No") << "\n";
    }

    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'has findHash(str)':
Main.cpp:39:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 | #define FOR(i,a,b) for (int i = (a); i < (b); ++i)
      |                                        ^
Main.cpp:40:18: note: in expansion of macro 'FOR'
   40 | #define F0R(i,a) FOR(i,0,a)
      |                  ^~~
Main.cpp:222:5: note: in expansion of macro 'F0R'
  222 |     F0R(i, sz(a)) {
      |     ^~~
Main.cpp: In function 'str add(str, str)':
Main.cpp:39:40: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 | #define FOR(i,a,b) for (int i = (a); i < (b); ++i)
      |                                        ^
Main.cpp:40:18: note: in expansion of macro 'FOR'
   40 | #define F0R(i,a) FOR(i,0,a)
      |                  ^~~
Main.cpp:233:5: note: in expansion of macro 'F0R'
  233 |     F0R(i, sz(a)) {
      |     ^~~
Main.cpp: In function 'void setIn(str)':
Main.cpp:59:28: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   59 | void setIn(str s) { freopen(s.c_str(),"r",stdin); }
      |                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
Main.cpp: In function 'void setOut(str)':
Main.cpp:60:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   60 | void setOut(str s) { freopen(s.c_str(),"w",stdout); }
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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