Submission #844856

#	Time	Username	Problem	Language	Result	Execution time	Memory
844856		ogkostya	Overtaking (IOI23_overtaking)	C++17	0 / 100	1 ms	604 KiB

overtaking

#include "overtaking.h"
#include <algorithm>
#include <utility>
#include <list>
#include <climits>

std::vector<std::vector<std::pair<long long, long long>>> SS(1001, std::vector<std::pair<long long, long long>>());

struct sort1
{
    inline bool operator() (const std::pair<long long, int>& a, const std::pair<long long, int>& b)
    {
        if (a.first == b.first)
            return a.second < b.second;
        return a.first < b.first;
    }
};

class leaf
{
public:
    leaf(long long _a, long long _b, long long _r)
    {
        a = _a;
        b = _b;
        r = _r;
    }

    long long a, b, r;
};

struct sort2
{
    inline bool operator() (leaf const& a, leaf const& b)
    {
        return b.r < a.r;
    }
};

int _M;
std::vector<int> _S;
int _X;

std::vector<leaf> ans;

std::vector<leaf> J(std::vector<leaf> & X)
{
    std::vector<leaf> Y;

    if (X.size() > 0)
    {
        std::sort(X.begin(), X.end(), sort2());

        long long a, b, r = -1, ma = LLONG_MAX;
        for (size_t i = 0; i < X.size(); i++)
        {
            if (X[i].r != r)
            {
                if (r == -1)
                {
                    r = X[i].r;
                    a = X[i].a;
                    b = X[i].b;
                }
                else
                {
                    if (ma > a)
                    {
                        if (b >= ma)
                            b = ma - 1;
                        Y.push_back(leaf(a, b, r));
                        ma = a;
                    }

                    r = X[i].r;
                    a = X[i].a;
                    b = X[i].b;
                }
            }
            else
            {
                if (a > X[i].a)
                    a = X[i].a;
                if (b < X[i].b)
                    b = X[i].b;
            }
        }

        if (ma > a)
        {
            if (b >= ma)
                b = ma - 1;
            Y.push_back(leaf(a, b, r));
        }
        std::reverse(Y.begin(), Y.end());
    }
    
    return Y;
}

void init(int L, int N, std::vector<long long> T, std::vector<int> W, int X, int M, std::vector<int> S)
{
    _X = X;
    _M = M;
    _S = S;

    std::vector<std::pair<long long, int>> TW;
    TW.reserve(N);
    for (int i = 0; i < N; i++)
    {
        if (W[i] < X)
            continue;
        TW.push_back(std::make_pair(T[i], W[i]));
    }
    long long mb = 0;

    std::vector<leaf> next;
    std::vector<leaf> curr;
    long long mr = 0;
    int curr_i;
    for (int j = 1; j < M; j++)
    {
        std::sort(TW.begin(), TW.end(), sort1());
        mb = 0;
        mr = 0;
        curr_i = 0;
        for (int i = 0; i < TW.size(); i++)
        {
            long long a = TW[i].first;
            long long b = a + 1LL * (_S[j] - _S[j - 1]) * TW[i].second;

            if (b < mb)
                b = mb;
            else
                mb = b;

            if (SS[j].size() == 0 || SS[j].back().second != b && (i + 1 == TW.size() || TW[i].first != TW[i + 1].first))
            {
                SS[j].push_back(std::make_pair(a, b));

                long long fa = a - 1LL * X * _S[j - 1] + 1;
                long long fb = b - 1LL * X * _S[j];
                long long fc = b + 1LL * (_S[M - 1] - _S[j]) * X;
                if (fc < mr)
                {
                    leaf front = leaf(fa, fb, b);
                    next.push_back(front);
                }
                else
                {
                    leaf front = leaf(fa, fb, fc);
                    ans.push_back(front);
                }
            }

            while (curr_i < curr.size())
            {
                if (curr[curr_i].r < a)
                {
                    long long fc = curr[curr_i].r + 1LL * (_S[M - 1] - _S[j - 1]) * X;
                    if (fc >= mr)
                    {
                        curr[curr_i].r = fc;
                        ans.push_back(curr[curr_i]);
                        curr_i++;
                        continue;
                    }
                    curr[curr_i].r = curr[curr_i].r + 1LL * (_S[j] - _S[j - 1]) * X;
                    next.push_back(curr[curr_i]);
                    curr_i++;
                    continue;
                }
                else
                {
                    if (i + 1 == TW.size() || TW[i + 1].first > curr[curr_i].r)
                    {
                        long long fc = curr[curr_i].r + 1LL * (_S[j] - _S[j - 1]) * X;
                        if (fc < b)
                            fc = b;
                        curr[curr_i].r = fc;
                        next.push_back(curr[curr_i]);
                        curr_i++;
                        continue;
                    }
                    else
                    {
                        break;
                    }
                }
            }

            long long c = b + 1LL * (_S[M - 1] - _S[j]) * TW[i].second;
            if (mr < c)
                mr = c;
            TW[i].first = b;
        }

        curr = J(next);
    }
    
    ans = J(ans);
    
}

long long arrival_time(long long Y)
{
    long long a = Y;
    long long b = a + 1LL * _S[_M - 1] * _X;

    if (ans[0].a <= a)
    {
        int l = 0, r = ans.size()-1;
        while (l < r)
        {
            int m = (l + r + 1) / 2;
            if (m == ans.size())
            {
                break;
            }
            else if (ans[m].a <= a)
            {
                l = m;
            }
            else
            {
                r = m - 1;
            }
        }

        if (ans[l].b >= a)
            b = ans[l].r;
    }

    return b;
}

Compilation message (stderr)

overtaking.cpp: In function 'void init(int, int, std::vector<long long int>, std::vector<int>, int, int, std::vector<int>)':
overtaking.cpp:127:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  127 |         for (int i = 0; i < TW.size(); i++)
      |                         ~~^~~~~~~~~~~
overtaking.cpp:137:73: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  137 |             if (SS[j].size() == 0 || SS[j].back().second != b && (i + 1 == TW.size() || TW[i].first != TW[i + 1].first))
      |                                                                   ~~~~~~^~~~~~~~~~~~
overtaking.cpp:137:63: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  137 |             if (SS[j].size() == 0 || SS[j].back().second != b && (i + 1 == TW.size() || TW[i].first != TW[i + 1].first))
      |                                      ~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
overtaking.cpp:156:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<leaf>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  156 |             while (curr_i < curr.size())
      |                    ~~~~~~~^~~~~~~~~~~~~
overtaking.cpp:175:31: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  175 |                     if (i + 1 == TW.size() || TW[i + 1].first > curr[curr_i].r)
      |                         ~~~~~~^~~~~~~~~~~~
overtaking.cpp: In function 'long long int arrival_time(long long int)':
overtaking.cpp:216:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<leaf>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  216 |             if (m == ans.size())
      |                 ~~^~~~~~~~~~~~~
overtaking.cpp: In function 'std::vector<leaf> J(std::vector<leaf>&)':
overtaking.cpp:91:13: warning: 'b' may be used uninitialized in this function [-Wmaybe-uninitialized]
   91 |             if (b >= ma)
      |             ^~
overtaking.cpp:24:11: warning: 'a' may be used uninitialized in this function [-Wmaybe-uninitialized]
   24 |         a = _a;
      |         ~~^~~~
overtaking.cpp:54:19: note: 'a' was declared here
   54 |         long long a, b, r = -1, ma = LLONG_MAX;
      |                   ^

• Subtask 0: 0 / 0
• Subtask 1: 0 / 9
• Subtask 2: 0 / 10
• Subtask 3: 0 / 20
• Subtask 4: 0 / 26
• Subtask 5: 0 / 35