Submission #1275804

#	Time	Username	Problem	Language	Result	Execution time	Memory
1275804		beny	Jakarta Skyscrapers (APIO15_skyscraper)	C++20	10 / 100	4 ms	616 KiB

skyscraper

#include<bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp> 
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

//#pragma GCC optimize("O3")
//#pragma GCC optimization("Ofast,unroll-loops")
//#pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")

#define ll long long
//#define smid (nl + nr) / 2
//#define lc id * 2
//#define rc id * 2 + 1
#define migmig std::ios_base::sync_with_stdio(false);std::cin.tie(NULL);std::cout.tie(NULL);
template <class T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

const int N = 30005;
bitset<N>mark[N];

vector<int> doge[N];

void solve() {
    int n, m; scanf("%d%d", &n, &m);

    int b0, p0, b1, p1;
    for (int i = 0; i < m; i++) {
        int b, p; scanf("%d%d", &b, &p);
        doge[b].push_back(p);
        if (i == 1) {
            b1 = b;
            p1 = p;
        }
        if (i == 0) {
            b0 = b;
            p0 = p;
        }
    }

    for (int i = 0; i <= n; i++) {
        for (int j = 0; j <= 30000; j++) {
            mark[i][j] = 0;
        }
    }

    queue<array<int, 3>> q;
    q.push({ 0, b0, p0 });
    mark[b0][p0] = 1;
    while (!q.empty()) {
        int d = q.front()[0];
        int v = q.front()[1];
        int p = q.front()[2];
        q.pop();

        if (v == b1) {
            printf("%d", d); return;
        }

        if (v - p >= 0) {
            if (!mark[v - p][p]) {
                if (v - p == b1) {
                    printf("%d", d + 1); return;
                }
                q.push({ d + 1, v - p, p });
                mark[v - p][p] = 1;
            }
        }
        if (v + p < n) {
            if (!mark[v + p][p]) {
                if (v + p == b1) {
                    printf("%d", d + 1); return;
                }
                q.push({ d + 1, v + p, p });
                mark[v + p][p] = 1;
            }
        }

        for (int pp : doge[v]) {
            if (!mark[v][pp]) {
                mark[v][pp] = 1;
                if (v - pp >= 0 && !mark[v - pp][pp]) {
                    q.push({ d + 1, v - pp, pp });
                    mark[v - pp][pp] = 1;
                }
                if (v + pp < n && !mark[v + pp][pp]) {
                    q.push({ d + 1, v + pp, pp });
                    mark[v + pp][pp] = 1;
                }
            }
        }
        doge[v].clear();
    }

    printf("-1");
}

int main() {
    migmig;

    int T = 1;
    //cin >> T;
    while (T--) {
        solve();
    }
}

Compilation message (stderr)

skyscraper.cpp: In function 'void solve()':
skyscraper.cpp:25:20: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |     int n, m; scanf("%d%d", &n, &m);
      |               ~~~~~^~~~~~~~~~~~~~~~
skyscraper.cpp:29:24: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   29 |         int b, p; scanf("%d%d", &b, &p);
      |                   ~~~~~^~~~~~~~~~~~~~~~

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