제출 #418128

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
418128		usachevd0	Sky Walking (IOI19_walk)	C++17	24 / 100	3284 ms	840888 KiB

walk

#include <bits/stdc++.h>
#ifndef LOCAL
    #include "walk.h"
#endif

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define all(a) (a).begin(), (a).end()
#define Time (clock() * 1.0 / CLOCKS_PER_SEC)
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pil = pair<int, ll>;
using pli = pair<ll, int>;
using pll = pair<ll, ll>;
using ld = long double;
template<typename T1, typename T2> bool chkmin(T1& x, T2 y) {
    return y < x ? (x = y, true) : false;
}
template<typename T1, typename T2> bool chkmax(T1& x, T2 y) {
    return y > x ? (x = y, true) : false;
}
void debug_out() {
    cerr << endl;
}
template<typename T1, typename... T2> void debug_out(T1 A, T2... B) {
    cerr << ' ' << A;
    debug_out(B...);
}
template<typename T> void mdebug_out(T* a, int n) {
    for (int i = 0; i < n; ++i)
        cerr << a[i] << ' ';
    cerr << endl;
}
#ifdef LOCAL
    #define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
    #define mdebug(a, n) cerr << #a << ": ", mdebug_out(a, n)
#else
    #define debug(...) 1337
    #define mdebug(a, n) 1337
#endif
template<typename T> ostream& operator << (ostream& stream, const vector<T>& v) {
    for (auto& x : v)
        stream << x << ' ';
    return stream;
}
template<typename T1, typename T2> ostream& operator << (ostream& stream, const pair<T1, T2>& p) {
    return stream << p.first << ' ' << p.second;
}

const ll INF64 = 1e18;
const int maxN = 100005;
int n, m;

const int maxV = 4e6 + 6;
int V;
vector<pii> G[maxV];
ll dist[maxV];
priority_queue<pli> pq;

map<int, int> ptIdx[maxN];
int getIdx(int x, int y) {
    if (ptIdx[x].count(y))
        return ptIdx[x][y];
    // debug(x, y, V);
    return ptIdx[x][y] = V++;
}

void addEdge(int u, int v, int w) {
    // debug(u, v, w);
    G[u].emplace_back(v, w);
    G[v].emplace_back(u, w);
}

ll min_distance(vector<int> X, vector<int> H, vector<int> L, vector<int> R, vector<int> Y, int SI, int TI) {
    n = X.size(), m = L.size();
    
    int S, T;
    for (int i = 0; i < n; ++i) {
        int v = getIdx(i, 0);
        if (i == SI)
            S = v;
        if (i == TI)
            T = v;
    }
    // debug(S, T);
    vector<int> ordy(m);
    iota(all(ordy), 0);
    sort(all(ordy), [&](int j1, int j2) -> bool {
        return Y[j1] > Y[j2];
    });
    vector<int> ordh(n);
    iota(all(ordh), 0);
    sort(all(ordh), [&](int i1, int i2) -> bool {
        return H[i1] > H[i2];
    });
    set<int> active;
    int hptr = 0;
    for (int j : ordy) {
        int l = L[j], r = R[j], y = Y[j];
        
        for (; hptr < ordh.size(); ++hptr) {
            int i = ordh[hptr];
            if (H[i] >= y)
                active.insert(i);
            else
                break;
        }
        
        int last_i = l, last_v = getIdx(l, y);
        for (auto it = active.upper_bound(l); it != active.end() && (*it) <= r; it = next(it)) {
            int i = *it;
            int v = getIdx(i, y);
            addEdge(last_v, v, X[i] - X[last_i]);
            last_v = v;
            last_i = i;
        }
        // for (int i = l + 1; i <= r; ++i) {
        //     if (H[i] >= y) {
        //         int v = getIdx(i, y);
        //         addEdge(last_v, v, X[i] - X[last_i]);
        //         last_v = v;
        //         last_i = i;
        //     }
        // }
    }
    for (int i = 0; i < n; ++i) {
        int last_y = -1, last_v = -1;
        for (auto& [y, v] : ptIdx[i]) {
            if (last_y != -1) {
                addEdge(last_v, v, y - last_y);
            }
            last_y = y;
            last_v = v;
        }
    }
    
    fill(dist, dist + V, INF64);
    dist[S] = 0;
    pq.push({0, S});
    while (!pq.empty()) {
        ll _d = -pq.top().fi;
        int v = pq.top().se;
        pq.pop();
        if (_d != dist[v]) continue;
        // debug(v, dist[v]);
        if (v == T) return dist[v];
        for (auto& [u, w] : G[v])
            if (chkmin(dist[u], dist[v] + w))
                pq.push({-dist[u], u});
    }
    return -1;
}


#ifdef LOCAL

int32_t main() {
#ifdef LOCAL
    freopen("in", "r", stdin);
#endif
    ios::sync_with_stdio(0);
    cin.tie(0);
    
        int n, m;
    assert(2 == scanf("%d%d", &n, &m));
    vector<int> x(n), h(n);
    for (int i = 0; i < n; i++)
        assert(2 == scanf("%d%d", &x[i], &h[i]));
    vector<int> l(m), r(m), y(m);
    for (int i = 0; i < m; i++)
        assert(3 == scanf("%d%d%d", &l[i], &r[i], &y[i]));
    int s, g;
    assert(2 == scanf("%d%d", &s, &g));
    fclose(stdin);

    long long result = min_distance(x, h, l, r, y, s, g);

    printf("%lld\n", result);
    fclose(stdout);
    
    return 0;
}

#endif

컴파일 시 표준 에러 (stderr) 메시지

walk.cpp: In function 'll min_distance(std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, std::vector<int>, int, int)':
walk.cpp:106:21: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  106 |         for (; hptr < ordh.size(); ++hptr) {
      |                ~~~~~^~~~~~~~~~~~~
walk.cpp:151:9: warning: 'T' may be used uninitialized in this function [-Wmaybe-uninitialized]
  151 |         if (v == T) return dist[v];
      |         ^~

• Subtask 1: 10 / 10
• Subtask 2: 14 / 14
• Subtask 3: 0 / 15
• Subtask 4: 0 / 18
• Subtask 5: 0 / 43