Submission #960488

#	Time	Username	Problem	Language	Result	Execution time	Memory
960488		quanlt206	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	100 / 100	673 ms	26404 KiB

skyscraper

#include<bits/stdc++.h>
#define X first
#define Y second
#define all(x) begin(x), end(x)
#define FOR(i, a, b) for(int i = (a); i <= (b); i++)
#define FORD(i, b, a) for(int i = (b); i >= (a); i--)
#define REP(i, a, b) for (int i = (a); i < (b); i++)
#define mxx max_element
#define mnn min_element
#define SQR(x) (1LL * (x) * (x))
#define MASK(i) (1LL << (i))
#define Point Vector
#define left Left
#define right Right
#define div Div

using namespace std;

typedef long long ll;
typedef unsigned long long ull;
typedef double db;
typedef long double ld;
typedef pair<db, db> pdb;
typedef pair<ld, ld> pld;
typedef pair<int, int> pii;
typedef pair<int, pii> piii;
typedef pair<ll, ll> pll;
typedef pair<ll, pll> plll;
typedef pair<ll, int> pli;
typedef pair<ll, pii> plii;

template<class A, class B>
    bool maximize(A& x, B y) {
        if (x < y) return x = y, true; else return false;
    }
template<class A, class B>
    bool minimize(A& x, B y) {
        if (x > y) return x = y, true; else return false;
    }
/* END OF TEMPLATE */

const int N = 3e4 + 7;
const int M = 3e4 + 7;
const int Q = 175;

int n, m, a[M], b[M];

vector<int> v[N];

int col0 = 0, col1 = 1;

int d[N][Q];

void bfs(int s, int x, int t) {
    int S = sqrt(n);
    FOR(i, 0, n)
        FOR(j, 0, S + 1) d[i][j] = 1e9;
    priority_queue<piii, vector<piii>, greater<piii>> pq;
    if (x <= S) {
        d[s][x] = 0;
        pq.push({0, {s, x}});
    }
    else {
        d[s][S + 1] = 0;
        pq.push({0, {s, S + 1}});
        int u = x;
        int cnt = 1, w = 0;
        for (int t = s - u; t >= 0; t-=u) {
            if (minimize(d[t][S + 1], w + cnt)) pq.push({d[t][S + 1], {t, S + 1}});
            cnt++;
        }
        cnt = 1;
        for (int t = s + u; t < n; t+=u) {
            if (minimize(d[t][S + 1], w + cnt)) pq.push({d[t][S + 1], {t, S + 1}});
            cnt++;
        }
    }
    while (!pq.empty()) {
        piii tmp = pq.top();
        pq.pop();
        int w = tmp.X, s = tmp.Y.X, x = tmp.Y.Y;
//        cout<<s<<" "<<x<<" "<<w<<"\n";
        if (w != d[s][x]) continue;
        if (x <= S) {
            if (s - x >= 0 && minimize(d[s - x][x], w + 1)) pq.push({w + 1, {s - x, x}});
            if (s + x < n && minimize(d[s + x][x], w + 1)) pq.push({w + 1, {s + x, x}});
        }
        for (auto u : v[s])
            if (u <= S) {
                if (minimize(d[s][u], w)) pq.push({w, {s, u}});
            }
            else {
                int cnt = 1;
                for (int t = s - u; t >= 0; t-=u) {
                    if (minimize(d[t][S + 1], w + cnt)) pq.push({d[t][S + 1], {t, S + 1}});
                    cnt++;
                }
                cnt = 1;
                for (int t = s + u; t < n; t+=u) {
                    if (minimize(d[t][S + 1], w + cnt)) pq.push({d[t][S + 1], {t, S + 1}});
                    cnt++;
                }
            }
        v[s].clear();
    }
    int res = 1e9;
    FOR(j, 0, S + 1) minimize(res, d[t][j]);
    cout<<(res == 1e9 ? -1 : res);
}

int main() {
//    freopen("APIO15_SKYSCRAPER.inp", "r", stdin);
//    freopen("APIO15_SKYSCRAPER.out", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cin>>n>>m;
    REP(i, 0, m) {
        cin>>a[i]>>b[i];
        v[a[i]].push_back(b[i]);
    }
    bfs(a[0], b[0], a[1]);
    return 0;

}

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