Submission #110199

#	Time	Username	Problem	Language	Result	Execution time	Memory
110199		SamAnd	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	857 ms	226132 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
const int N = 30004;
struct ban
{
    int x, p;
    int d;
    ban(){}
    ban(int x, int p, int d)
    {
        this->x = x;
        this->p = p;
        this->d = d;
    }
};

int n, m;
int b[N], p[N];

vector<int> a[N];

bool c[N][N];

int bfs()
{
    queue<ban> q;
    for (int i = 0; i < a[b[0]].size(); ++i)
    {
        if (!c[b[0]][a[b[0]][i]])
        {
            c[b[0]][a[b[0]][i]] = true;
            q.push(ban(b[0], a[b[0]][i], 0));
        }
    }
    while (!q.empty())
    {
        ban t;
        t = q.front();
        q.pop();
        if (t.x == b[1])
            return t.d;
        if (t.x + t.p < n)
        {
            if (!c[t.x + t.p][t.p])
            {
                c[t.x + t.p][t.p] = true;
                q.push(ban(t.x + t.p, t.p, t.d + 1));
            }
            for (int i = 0; i < a[t.x + t.p].size(); ++i)
            {
                ban h(t.x + t.p, a[t.x + t.p][i], t.d + 1);
                if (!c[h.x][h.p])
                {
                    c[h.x][h.p] = true;
                    q.push(h);
                }
            }
        }
        if (t.x - t.p >= 0)
        {
            if (!c[t.x - t.p][t.p])
            {
                c[t.x - t.p][t.p] = true;
                q.push(ban(t.x - t.p, t.p, t.d + 1));
            }
            for (int i = 0; i < a[t.x - t.p].size(); ++i)
            {
                ban h(t.x - t.p, a[t.x - t.p][i], t.d + 1);
                if (!c[h.x][h.p])
                {
                    c[h.x][h.p] = true;
                    q.push(h);
                }
            }
        }
    }
    return -1;
}

int main()
{
    cin >> n >> m;
    for (int i = 0; i < m; ++i)
    {
        cin >> b[i] >> p[i];
        a[b[i]].push_back(p[i]);
    }

    cout << bfs() << endl;
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int bfs()':
skyscraper.cpp:27:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     for (int i = 0; i < a[b[0]].size(); ++i)
                     ~~^~~~~~~~~~~~~~~~
skyscraper.cpp:49:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 0; i < a[t.x + t.p].size(); ++i)
                             ~~^~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:66:31: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
             for (int i = 0; i < a[t.x - t.p].size(); ++i)
                             ~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 21 / 21
• Subtask 5: 43 / 43