Submission #289280

#	Time	Username	Problem	Language	Result	Execution time	Memory
289280		SamAnd	Toy Train (IOI17_train)	C++17	16 / 100	28 ms	25848 KiB

train

#include "train.h"
#include <bits/stdc++.h>
using namespace std;
#define m_p make_pair
#define fi first
#define se second
#define all(x) (x).begin(),(x).end()
#define sz(x) ((int)(x).size())
typedef long long ll;
const int N = 5003;

int n;
vector<int> a, r;
vector<int> g[N];
bool u[N][N];
vector<int> rg[N];

vector<int> solv1()
{
    vector<int> ans(n);
    for (int i = n - 1; i >= 0; --i)
    {
        if (a[i])
        {
            if (r[i])
            {
                if (u[i][i])
                {
                    ans[i] = 1;
                }
                else
                {
                    ans[i] = ans[i + 1];
                }
            }
            else
            {
                if (u[i][i + 1])
                {
                    ans[i] = ans[i + 1];
                }
                else
                {
                    ans[i] = 0;
                }
            }
        }
        else
        {
            if (!r[i])
            {
                if (u[i][i])
                {
                    ans[i] = 0;
                }
                else
                {
                    ans[i] = ans[i + 1];
                }
            }
            else
            {
                if (u[i][i + 1])
                {
                    ans[i] = ans[i + 1];
                }
                else
                {
                    ans[i] = 1;
                }
            }
        }
    }
    return ans;
}

int c[N];
vector<int> v;
void dfs0(int x)
{
    c[x] = 1;
    for (int i = 0; i < g[x].size(); ++i)
    {
        int h = g[x][i];
        if (!c[h])
            dfs0(h);
    }
    v.push_back(x);
}

int k;
void dfs1(int x)
{
    c[x] = k;
    for (int i = 0; i < rg[x].size(); ++i)
    {
        int h = rg[x][i];
        if (!c[h])
            dfs1(h);
    }
}

vector<int> xg[N];
int q[N];
void kond()
{
    for (int x = 0; x < n; ++x)
    {
        if (!c[x])
            dfs0(x);
    }
    reverse(all(v));
    memset(c, 0, sizeof c);
    for (int i = 0; i < n; ++i)
    {
        int x = v[i];
        if (!c[x])
        {
            ++k;
            dfs1(x);
        }
    }

    for (int x = 0; x < n; ++x)
    {
        for (int i = 0; i < g[x].size(); ++i)
        {
            int y = g[x][i];
            if (c[x] != c[y])
            {
                xg[c[x]].push_back(c[y]);
            }
            else
                ++q[c[x]];
        }
    }
}

int ans[N];
bool cc[N];
bool uu[N];
void dfs3(int x)
{
    cc[x] = true;
    if (q[x] && uu[x])
        ans[x] = 1;
    for (int i = 0; i < xg[x].size(); ++i)
    {
        int h = xg[x][i];
        if (!cc[h])
            dfs3(h);
        if (ans[h])
            ans[x] = 1;
    }
}

vector<int> solv3()
{
    kond();
    for (int x = 0; x < n; ++x)
    {
        if (r[x])
            uu[c[x]] = true;
    }
    for (int i = 1; i <= k; ++i)
    {
        if (!cc[i])
        {
            dfs3(i);
        }
    }

    vector<int> ansv;
    for (int x = 0; x < n; ++x)
    {
        ansv.push_back(ans[c[x]]);
    }
    return ansv;
}

void dfs2(int x)
{
    cc[x] = true;
    for (int i = 0; i < g[x].size(); ++i)
    {
        int h = g[x][i];
        if (r[h])
            continue;
        if (!cc[h])
            dfs2(h);
        else
            uu[c[x]] = true;
    }
}

void dfs4(int x)
{
    cc[x] = true;
    if (uu[x])
        ans[x] = 0;
    for (int i = 0; i < xg[x].size(); ++i)
    {
        int h = xg[x][i];
        if (!cc[h])
            dfs4(h);
        if (ans[h])
            ans[x] = 0;
    }
}

vector<int> solv4()
{
    kond();
    for (int x = 0; x < n; ++x)
    {
        if (r[x])
            continue;
        if (!cc[x])
            dfs2(x);
    }
    memset(cc, false, sizeof cc);
    for (int i = 1; i <= k; ++i)
        ans[i] = 1;
    for (int i = 1; i <= k; ++i)
    {
        if (!cc[i])
            dfs4(i);
    }

    vector<int> ansv;
    for (int x = 0; x < n; ++x)
    {
        ansv.push_back(ans[c[x]]);
    }
    return ansv;
}

std::vector<int> who_wins(std::vector<int> A, std::vector<int> R, std::vector<int> U, std::vector<int> V)
{
    a = A;
    r = R;

    n = sz(a);
    bool z1 = true;
    for (int i = 0; i < sz(U); ++i)
    {
        int x = U[i];
        int y = V[i];
        g[x].push_back(y);
        rg[y].push_back(x);
        u[x][y] = true;

        if (x != y && x + 1 != y)
            z1 = false;
    }

    bool z3 = true;
    bool z4 = true;
    for (int i = 0; i < n; ++i)
    {
        if (a[i])
        {
            z4 = false;
        }
        else
        {
            z3 = false;
        }
    }
    if (z3)
        return solv3();
    if (z1)
        return solv1();
    if (z4)
        return solv4();
}

Compilation message (stderr)

train.cpp: In function 'void dfs0(int)':
train.cpp:82:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   82 |     for (int i = 0; i < g[x].size(); ++i)
      |                     ~~^~~~~~~~~~~~~
train.cpp: In function 'void dfs1(int)':
train.cpp:95:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   95 |     for (int i = 0; i < rg[x].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~
train.cpp: In function 'void kond()':
train.cpp:126:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  126 |         for (int i = 0; i < g[x].size(); ++i)
      |                         ~~^~~~~~~~~~~~~
train.cpp: In function 'void dfs3(int)':
train.cpp:147:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  147 |     for (int i = 0; i < xg[x].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~
train.cpp: In function 'void dfs2(int)':
train.cpp:184:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  184 |     for (int i = 0; i < g[x].size(); ++i)
      |                     ~~^~~~~~~~~~~~~
train.cpp: In function 'void dfs4(int)':
train.cpp:201:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  201 |     for (int i = 0; i < xg[x].size(); ++i)
      |                     ~~^~~~~~~~~~~~~~
train.cpp: In function 'std::vector<int> who_wins(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>)':
train.cpp:276:1: warning: control reaches end of non-void function [-Wreturn-type]
  276 | }
      | ^

• Subtask 1: 5 / 5
• Subtask 2: 0 / 10
• Subtask 3: 11 / 11
• Subtask 4: 0 / 11
• Subtask 5: 0 / 12
• Subtask 6: 0 / 51