Submission #389644

#	Time	Username	Problem	Language	Result	Execution time	Memory
389644		2qbingxuan	Permutation Recovery (info1cup17_permutation)	C++14	100 / 100	2974 ms	164216 KiB

Main

// #define _GLIBCXX_DEBUG
#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>
#ifdef local
#define safe cerr<<__PRETTY_FUNCTION__<<" line "<<__LINE__<<" safe\n"
#define pary(a...) danb(#a, a)
#define debug(a...) qqbx(#a, a)
template <typename ...T> void qqbx(const char *s, T ...a) {
    int cnt = sizeof...(T);
    ((std::cerr << "\033[1;32m(" << s << ") = (") , ... , (std::cerr << a << (--cnt ? ", " : ")\033[0m\n")));
}
template <typename T> void danb(const char *s, T L, T R) {
    std::cerr << "\033[1;32m[ " << s << " ] = [ ";
    for (int f = 0; L != R; ++L)
        std::cerr << (f++ ? ", " : "") << *L;
    std::cerr << " ]\033[0m\n";
}
#else
#define debug(...) ((void)0)
#define safe ((void)0)
#define pary(...) ((void)0)
#endif // local
#define all(v) begin(v),end(v)
#define pb emplace_back
using namespace std;
using ll = int64_t;
const int maxn = 70025;

struct BigInteger : vector<int> {
    static constexpr int base = 1000000000;
    static constexpr int width = 9;
    BigInteger() {}
    explicit BigInteger(int x) : vector<int>{x} {}
    friend istream & operator>>(istream &I, BigInteger &n) {
        string s;
        I >> s;
        n.reserve(s.size() / 9);
        reverse(s.begin(), s.end());
        int cur = 0, cnt = 0, p = 1;
        for (char c: s) {
            cur = cur + (c - '0') * p;
            if (++cnt == width) {
                n.emplace_back(cur);
                cur = 0;
                cnt = 0;
                p = 1;
            } else {
                p *= 10;
            }
        }
        if (cnt)
            n.emplace_back(cur);
        return I;
    }
    BigInteger& operator+=(const BigInteger &rhs) {
        if (size() < rhs.size()) resize(rhs.size());
        int carry = 0;
        for (size_t i = 0; i < size(); i++) {
            at(i) += (i < rhs.size() ? rhs[i] : 0) + carry;
            carry = at(i) / base;
            at(i) %= base;
        }
        if (carry)
            push_back(carry);
        return *this;
    }
    BigInteger& operator-=(const BigInteger &rhs) {
        int carry = 0;
        for (size_t i = 0; i < size(); i++) {
            at(i) -= (i < rhs.size() ? rhs[i] : 0) + carry;
            if (at(i) < 0) {
                at(i) += base;
                carry = 1;
            } else {
                carry = 0;
            }
        }
        while (!empty() && back() == 0) pop_back();
        return *this;
    }
    friend bool operator<(const BigInteger &x, const BigInteger &y) {
        if (x.size() != y.size()) return x.size() < y.size();
        if (x.empty()) return false;
        for (int i = x.size()-1; i >= 0; i--)
            if (x[i] != y[i])
                return x[i] < y[i];
        return false;
    }
    friend bool operator>=(const BigInteger &x, const BigInteger &y) { return !(x < y); }
    friend bool operator>(const BigInteger &x, const BigInteger &y) { return y < x; }
    friend bool operator<=(const BigInteger &x, const BigInteger &y) { return !(y < x); }
    friend BigInteger operator+(BigInteger a, const BigInteger &b) {
        return a += b;
    }
    friend BigInteger operator-(BigInteger a, const BigInteger &b) {
        return a -= b;
    }
    friend ostream & operator<<(ostream &O, BigInteger n) {
        return O << n[0];
    }
};

vector<int> ans;
using Int = BigInteger;

struct Splay {
    struct node {
        int pa, ch[2];
        Int sum, val;
        int id;
        node() : pa(0), ch{0, 0}, sum(), val(), id() {}
        node(const Int & x, int pos) : pa(0), ch{0, 0}, sum(x), val(x), id(pos) {}
    } S[maxn];
    int tot;
    bool dir(int x) {
        return S[S[x].pa].ch[1] == x;
    }
    bool isRoot(int x) {
        return !x || !S[x].pa;
    }
    void pull(int x) {
        S[x].sum = S[S[x].ch[0]].sum + S[x].val + S[S[x].ch[1]].sum;
    }
    void rot(int x) {
        debug("rot", x);
        int y = S[x].pa, z = S[y].pa, d = dir(x);
        S[x].pa = z;
        if (!isRoot(y)) S[z].ch[dir(y)] = x;
        S[y].ch[d] = S[x].ch[!d];
        if (S[x].ch[!d]) S[S[x].ch[!d]].pa = y;
        S[y].pa = x;
        S[x].ch[!d] = y;
        pull(y);
        pull(x);
    }
    void splay(int x) {
        // debug("splay", x);
        while (!isRoot(x)) {
            if (int y = S[x].pa; !isRoot(y))
                rot(dir(x) != dir(y) ? x : y);
            rot(x);
        }
    }
    int endPoint(int x, bool d) {
        debug(x);
        while (S[x].ch[d]) x = S[x].ch[d];
        return x;
    }
    void insert(Int sum, int idx) {
        S[++tot] = node(sum, idx);
        if (tot == 1)
            return;
        if (sum == static_cast<Int>(1)) {
            safe;
            debug(sum, idx, "FRONT");
            splay(tot-1);
            int x = endPoint(tot-1, false);
            S[x].ch[0] = tot;
            S[tot].pa = x;
            pull(x);
            splay(tot);
            return;
        }
        int x = tot-1;
        splay(x);
        debug(x, sum);
        // dfs(x), cerr << '\n';
        int cnt=0;
        while (true) {
            // if (++cnt>=20) exit(0);
            debug(x, "IN");
            Int cur = S[S[x].ch[0]].sum + S[x].val;
            debug(cur+BigInteger(1), sum);
            if (cur + BigInteger(1) < sum) {
                sum -= cur;
                x = S[x].ch[1];
            } else if (cur + BigInteger(1) > sum) {
                x = S[x].ch[0];
            } else
                break;
        }
        splay(x);
        debug("POS", x);
        if (S[x].ch[1] == 0) {
            S[x].ch[1] = tot;
            S[tot].pa = x;
            pull(x);
        } else {
            int y = endPoint(S[x].ch[1], false);
            S[y].ch[0] = tot;
            S[tot].pa = y;
            pull(y);
            splay(tot);
        }
    }
    void dfs(int x) {
        if (!x) return;
        dfs(S[x].ch[0]);
        // cerr << S[x].id << ',' << S[x].val << ' ';
        ans.pb(S[x].id);
        dfs(S[x].ch[1]);
    }
} sp;

Int q[maxn];
signed main() {
    debug(0);
    ios_base::sync_with_stdio(0), cin.tie(0);
    int n;
    cin >> n;
    for (int i = 0; i < n; i++)
        cin >> q[i];
    for (int i = n-1; i >= 1; i--)
        q[i] -= q[i-1];

    for (int i = 0; i < n; i++) {
        sp.insert(q[i], i);
        debug(i);
        // sp.splay(1);
        // sp.dfs(1);
        // cerr << '\n';
    }
    sp.splay(1);
    sp.dfs(1);
    // return 0;
    /*
    vector<int> ans{0};
    for (int i = 1; i < n; i++) {
        // pary(q[i].begin(), q[i].end());
        if (q[i] == static_cast<Int>(1)) {
            ans.insert(ans.begin(), i);
            continue;
        }
        Int sum = static_cast<Int>(1);
        for (int j = 0; j < i; j++) {
            sum += q[ans[j]];
            // pary(sum.begin(), sum.end());
            if (sum == q[i]) {
                ans.insert(ans.begin() + j + 1, i);
                break;
            }
        }
    }
    */
    vector<int> p(n);
    for (int i = 0; i < n; i++)
        p[ans[i]] = i+1;
    for (int i = 0; i < n; i++)
        cout << p[i] << (i+1==n ? '\n' : ' ');
}

Compilation message (stderr)

permutation.cpp: In member function 'void Splay::splay(int)':
permutation.cpp:139:17: warning: init-statement in selection statements only available with '-std=c++17' or '-std=gnu++17'
  139 |             if (int y = S[x].pa; !isRoot(y))
      |                 ^~~
permutation.cpp: In member function 'void Splay::insert(Int, int)':
permutation.cpp:168:13: warning: unused variable 'cnt' [-Wunused-variable]
  168 |         int cnt=0;
      |             ^~~

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 18 / 18
• Subtask 4: 17 / 17
• Subtask 5: 11 / 11
• Subtask 6: 7 / 7
• Subtask 7: 16 / 16
• Subtask 8: 6 / 6