Submission #239246

#	Time	Username	Problem	Language	Result	Execution time	Memory
239246		ant101	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	396 ms	262148 KiB

skyscraper

#include <iostream>
#include <algorithm>
#include <cstring>
#include <iomanip>
#include <fstream>
#include <cmath>
#include <vector>
#include <set>
#include <unordered_set>
#include <unordered_map>
#include <map>
#include <stack>
#include <queue>
#include <assert.h>
#include <limits>
#include <cstdio>
using namespace std;

//#define RDEBUG 1
#ifdef RDEBUG
#define D(x) x
#else
#define D(x)
#endif
#define inf 0x7fffffff
#define MOD 1000000007

typedef long long ll;


ll add(ll a, ll b) {
    a += b;
    if(a >= MOD) {
        a -= MOD;
    }
    return a;
}
ll sub(ll a, ll b) {
    a -= b;
    if(a < 0) {
        a += MOD;
    }
    return a;
}

ll mul(ll a, ll b) {
    return (a * b)%MOD;
}

void add_self(ll& a, ll b) {
    a = add(a, b);
}
void sub_self(ll& a, ll b) {
    a = sub(a, b);
}
void mul_self(ll& a, ll b) {
    a = mul(a, b);
}


const ll MAXN = 30010;

ll sp[MAXN][175];
ll N, M;
pair<ll, ll> doge[MAXN];
vector<pair<pair<ll, ll>, ll>> adj[MAXN][175];

void dij(ll start) {
    for (ll i = 0; i<N; i++) {
        for (ll j = 0; j<=sqrt(N); j++) {
            sp[i][j] = 1e13;
        }
    }
    priority_queue<pair<ll, pair<ll, ll>>, vector<pair<ll, pair<ll, ll>>>, greater<pair<ll, pair<ll, ll>>>> pq;
    pq.push({0, {doge[start].first, 0}});
    sp[doge[start].first][0] = 0;
    while (pq.size() != 0) {
        ll d = pq.top().first, u = pq.top().second.first, p = pq.top().second.second;
        pq.pop();
        if (sp[u][p] != d) {
            continue;
        }
        if (p != 0) {
            if (u-p >= 0) {
                adj[u][p].push_back({{u-p, p}, 1});
            }
            if (u+p < N) {
                adj[u][p].push_back({{u+p, p}, 1});
            }
            adj[u][p].push_back({{u, 0}, 0});
        }
        for (auto edge : adj[u][p]) {
            ll v = edge.first.first, np = edge.first.second, w = edge.second;
            if (d+w < sp[v][np]) {
                sp[v][np] = d+w;
                pq.push({d+w, {v, np}});
            }
        }
        if (p != 0) {
            if (u-p >= 0) {
                adj[u][p].pop_back();
            }
            if (u+p < N) {
                adj[u][p].pop_back();
            }
            adj[u][p].push_back({{u, 0}, 0});
        }
    }
}

int main() {
    ios_base :: sync_with_stdio(false);
    cin.tie(nullptr);
    cin >> N >> M;
    for (ll i = 0; i<M; i++) {
        ll a, b;
        cin >> a >> b;
        doge[i] = {a, b};
        if (b<=sqrt(N)) {
            adj[a][0].push_back({{a, b}, 0});
        } else {
            for (ll j = 1; j<=N; j++) {
                ll hold = 0;
                if (a-b*j >= 0) {
                    hold++;
                    adj[a][0].push_back({{a-b*j, 0}, j});
                }
                if (a+b*j < N) {
                    hold++;
                    adj[a][0].push_back({{a+b*j, 0}, j});
                }
                if (!hold) {
                    break;
                }
            }
        }
    }
    dij(0);
    cout << (sp[doge[1].first][0] == 1e13 ? -1 : sp[doge[1].first][0]) << "\n";
    return 0;
}

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