Submission #297622

#	Time	Username	Problem	Language	Result	Execution time	Memory
297622		AaronNaidu	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	36 / 100	468 ms	245540 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;

int n, m, b, p;
vector<pair<int, int> > graph[30001];
int powers[30001];
int positions[30001];
priority_queue<pair<int, int> > q;
int dists[30001];
bool visited[30001];
set<int> powerPos[50000];
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    cin >> n >> m;
    for (int i = 0; i < m; i++)
    {
        cin >> b >> p;
        powers[i] = p;
        positions[i] = b;
        powerPos[positions[i]].insert(powers[i]);
    }
    for (int i = 0; i < n; i++)
    {
        dists[i] = 1000000000;
    }
    int checkCount = 0;
    for (int i = 0; i < m; i++)
    {
        int jumpCount = 0;
        for (int j = positions[i]+powers[i]; j < n; j+=powers[i])
        {
            jumpCount++;
            checkCount++;
            graph[positions[i]].push_back({j, jumpCount});
            //cout << "Connecting " << j << " to " << positions[i] << "\n";
            if (powerPos[j].find(powers[i]) != powerPos[j].end())
            {
                break;
            }
            
        }
        jumpCount = 0;
        for (int j = positions[i]-powers[i]; j >= 0; j-=powers[i])
        {
            jumpCount++;
            checkCount++;
            graph[positions[i]].push_back({j, jumpCount});
            //cout << "Connecting " << j << " to " << positions[i] << "\n";
            if (powerPos[j].find(powers[i]) != powerPos[j].end())
            {
                break;
            }
        }
        assert(checkCount < 15000000);
    }
    /*for (int i = 0; i < n; i++)
    {
        for (int j = 0; j < n; j++)
        {
            cout << matrix[i][j] << " ";
        }
        cout << "\n";
    }*/
    
    q.push({0, positions[0]});
    dists[positions[0]] = 0;
    while (!q.empty()) 
    {
        int x = q.top().second;
        //cout << "At node " << x << " which is " << dists[x] << " away\n";
        if (x == positions[1])
        {
            int ans = dists[positions[1]];
            cout << ans << "\n";
            return 0;
        }
        q.pop();
        if (visited[x])
        {
            continue;
        }
        visited[x] = true;
        for (auto i : graph[x])
        {
            if (!visited[i.first] and dists[x] + i.second < dists[i.first])
            {
                dists[i.first] = dists[x] + i.second;
                q.push({-dists[i.first], i.first});
                //cout << "Pushing " << i.first << " which is " << dists[i.first] << " away\n";
            }
        }   
    }
    cout << "-1\n";
}

• Subtask 1: 10 / 10
• Subtask 2: 12 / 12
• Subtask 3: 14 / 14
• Subtask 4: 0 / 21
• Subtask 5: 0 / 43