Submission #874320

#	Time	Username	Problem	Language	Result	Execution time	Memory
874320		RedGrey1993	Round words (IZhO13_rowords)	C++17	100 / 100	76 ms	22124 KiB

rowords

#include <bits/stdc++.h>
 
using namespace std;
 
template <typename T1, typename T2> istream &operator>>(istream &is, const pair<T1, T2> &pa) { is >> pa.first >> pa.second; return is; }
template <typename T> istream &operator>>(istream &is, vector<T> &vec) { for (auto &v : vec) is >> v; return is; }
template <typename T1, typename T2> ostream &operator<<(ostream &os, const pair<T1, T2> &pa) { os << "(" << pa.first << "," << pa.second << ")"; return os; }
template <typename T> ostream &operator<<(ostream &os, const vector<T> &vec) { os << "["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template <typename T> ostream &operator<<(ostream &os, const deque<T> &vec) { os << "deq["; for (auto v : vec) os << v << ","; os << "]"; return os; }
template <typename T> ostream &operator<<(ostream &os, const set<T> &vec) { os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template <typename T> ostream &operator<<(ostream &os, const multiset<T> &vec) { os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_set<T> &vec) { os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template <typename T> ostream &operator<<(ostream &os, const unordered_multiset<T> &vec) { os << "{"; for (auto v : vec) os << v << ","; os << "}"; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const unordered_map<TK, TV> &mp) { os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template <typename TK, typename TV> ostream &operator<<(ostream &os, const map<TK, TV> &mp) { os << "{"; for (auto v : mp) os << v.first << "=>" << v.second << ","; os << "}"; return os; }
template <typename T> void resize_array(vector<T> &vec, int len) { vec.resize(len); }
template <typename T, typename... Args> void resize_array(vector<T> &vec, int len, Args... args) { vec.resize(len); for (auto &v : vec) resize_array(v, args...); }
template <typename T1, typename T2> pair<T1, T2> operator+(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first + r.first, l.second + r.second); }
template <typename T1, typename T2> pair<T1, T2> operator-(const pair<T1, T2> &l, const pair<T1, T2> &r) { return make_pair(l.first - r.first, l.second - r.second); }
long long gcd(long long a, long long b) { return b ? gcd(b, a % b) : a; }
mt19937 mrand(random_device{}());
int rnd(int x) { return mrand() % x; }
 
template <unsigned int MOD>
class ModInt {
public:
    ModInt(unsigned long long _v = 0) { set_v((_v % MOD + MOD)); }
    explicit operator bool() const { return val != 0; }
    ModInt operator-() const { return ModInt() - *this; }
    ModInt operator+(const ModInt &r) const { return ModInt().set_v(val + r.val); }
    ModInt operator-(const ModInt &r) const { return ModInt().set_v(val + MOD - r.val); }
    ModInt operator*(const ModInt &r) const { return ModInt().set_v((unsigned int)((unsigned long long)(val)*r.val % MOD)); }
    ModInt operator/(const ModInt &r) const { return *this * r.inv(); }
    ModInt &operator+=(const ModInt &r) { return *this = *this + r; }
    ModInt &operator-=(const ModInt &r) { return *this = *this - r; }
    ModInt &operator*=(const ModInt &r) { return *this = *this * r; }
    ModInt &operator/=(const ModInt &r) { return *this = *this / r; }
    // ModInt &operator=(unsigned long long _v) { set_v((_v % MOD + MOD)); return *this; }
    unsigned int operator=(unsigned long long _v) { set_v((_v % MOD + MOD)); return val; }
    bool operator==(const ModInt &r) const { return val == r.val; }
    bool operator!=(const ModInt &r) const { return val != r.val; }
    ModInt pow(long long n) const {
        ModInt x = *this, r = 1;
        while (n) {
            if (n & 1)
                r *= x;
            x *= x;
            n >>= 1;
        }
        return r;
    }
    ModInt inv() const { return pow(MOD - 2); }
    unsigned int get_val() { return val; }
    friend ostream &operator<<(ostream &os, const ModInt &r) { return os << r.val; }
    friend istream &operator>>(istream &is, ModInt &r) { return is >> r.val; }
private:
    unsigned int val;
    ModInt &set_v(unsigned int _v) {
        val = (_v < MOD) ? _v : _v - MOD;
        return *this;
    }
};
constexpr unsigned int mod = 1e9+7;
using Mint = ModInt<mod>;
 
#define rep(i, a, n) for (int i = a; i < (n); i++)
#define per(i, a, n) for (int i = (n)-1; i >= a; i--)
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define fi first
#define se second
#define sz(x) ((int)(x).size())
typedef vector<int> vi;
typedef long long ll;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef double db;
#if DEBUG
#define dbg(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ") " << __FILE__ << endl;
#else
#define dbg(x)
#endif
 
using Mint2 = ModInt<mod-1>;
class Solution {
    struct Line {
        long long m, c;
        long long Eval(long long x) { return m * x + c; }
        long double IntersectX(Line l) { return (long double)(c - l.c) / (l.m - m); }
    };

public:
    void Solve() {
        string s,t;
        while(cin>>s>>t) {
            s += s;
            // dbg(s);
            int n = sz(s), m=sz(t);

            auto clcs = [&] () {
                vector<vi> dp(n+1, vi(m+1));
                vector<vi> parent(n+1, vi(m+1));
                rep(i,1,n+1) parent[i][0] = 2;

                rep(i,0,n) {
                    rep(j,0,m) {
                        if (s[i] == t[j]) dp[i+1][j+1] = dp[i][j] + 1;
                        else dp[i+1][j+1] = max(dp[i][j+1], dp[i+1][j]);

                        if (dp[i+1][j+1] == dp[i+1][j]) parent[i+1][j+1] = 0;
                        else if (s[i] == t[j] && dp[i+1][j+1] == dp[i][j] + 1) parent[i+1][j+1] = 1;
                        else parent[i+1][j+1] = 2;
                    }
                }

                auto lcs = [&] (int root) {
                    int x = root + n/2;
                    int y = m;
                    int cnt = 0;
                    while (x > root && y > 0) {
                        if (parent[x][y] == 1) {
                            cnt++;
                            x--; y--;
                            // dbg(mp(x,y));
                            // dbg(cnt);
                        } else if (parent[x][y] == 0) y--;
                        else x--;
                    }
                    return cnt;
                };

                auto reroot = [&] (int root) {
                    int x = root;
                    int y = 0;

                    while (y <= m && parent[x][y] != 1) y++;
                    if (y > m) return;

                    parent[x][y] = 0;
                    while (x < n && y < m) {
                        if (parent[x+1][y] == 2) {
                            x++;
                            parent[x][y] = 0;
                        } else if (parent[x+1][y+1] == 1) {
                            x++; y++;
                            parent[x][y] = 0;
                        } else {
                            y++;
                        }
                    }

                    while (x < n && parent[x+1][y] == 2) {
                        x++;
                        parent[x][y] = 0;
                    }
                };

                int ans = 0;
                ans = max(ans, lcs(0));
                rep(root, 1, n/2) {
                    reroot(root);
                    ans = max(ans, lcs(root));
                }
                // dbg(ans);
                return ans;
            };

            int ans = clcs();
            reverse(all(s));
            ans = max(ans, clcs());
            cout << ans << endl;
        }
    }
private:
};
 
// #define USACO 1
void set_io(const string &name = "") {
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
#if FILE_IO || USACO
    if (!name.empty()) {
        freopen((name + ".in").c_str(), "r", stdin);
        freopen((name + ".out").c_str(), "w", stdout);
    }
#endif
}

int main() {
#if USACO
    set_io("time");
#else
    set_io("input");
#endif
    Solution().Solve();

    return 0;
}

• Subtask 1: 100 / 100