Submission #554463

#	Time	Username	Problem	Language	Result	Execution time	Memory
554463		SmolBrain	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	36 / 100	163 ms	9732 KiB

skyscraper

// Om Namah Shivaya
// GM in 96 days

#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;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;

typedef long long int ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define endl '\n'
#define pb push_back
#define conts continue
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "YES" << endl
#define no cout << "NO" << endl
#define ff first
#define ss second
#define ceil2(x,y) ((x+y-1) / (y))
#define sz(a) a.size()
#define setbits(x) __builtin_popcountll(x)
#ifndef ONLINE_JUDGE
#define debug(x) cout << #x <<" = "; print(x); cout << endl
#else
#define debug(x)
#endif

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

bool iseven(ll n) {if ((n & 1) == 0) return true; return false;}

void print(ll t) {cout << t;}
void print(int t) {cout << t;}
void print(string t) {cout << t;}
void print(char t) {cout << t;}
void print(double t) {cout << t;}
void print(ld t) {cout << t;}

template <class T, class V> void print(pair <T, V> p);
template <class T> void print(vector <T> v);
template <class T> void print(set <T> v);
template <class T, class V> void print(map <T, V> v);
template <class T> void print(multiset <T> v);
template <class T, class V> void print(pair <T, V> p) {cout << "{"; print(p.ff); cout << ","; print(p.ss); cout << "}";}
template <class T> void print(vector <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(set <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T> void print(multiset <T> v) {cout << "[ "; for (T i : v) {print(i); cout << " ";} cout << "]";}
template <class T, class V> void print(map <T, V> v) {cout << "[ "; for (auto i : v) {print(i); cout << " ";} cout << "]";}
template<typename T> void amin(T &a, T b) { a = min(a, b); }
template<typename T> void amax(T &a, T b) { a = max(a, b); }

void usaco(string filename) {
    freopen((filename + ".in").c_str(), "r", stdin);
    freopen((filename + ".out").c_str(), "w", stdout);
}

const int MOD = 1e9 + 7;
const int maxn = 2005;
const int inf1 = 1e9 + 5;
const ll inf2 = ll(1e18) + 5;

vector<pii> dummy[maxn * 2];
bool vis[maxn * 2][maxn];

void solve(int test_case)
{
    // editorial approach
    int n, m; cin >> n >> m;
    vector<pii> a(m);

    rep(i, n) dummy[i].pb({i + n, 0});

    rep(i, m) {
        int b, p; cin >> b >> p;
        a[i] = {b, p};

        // b + n = dummy vertex
        dummy[b + n].pb({b, i});
    }

    deque<array<int, 3>> dq;
    dq.pb({0, a[0].ff, 0});

    while (!dq.empty()) {
        auto [cost, b, id] = dq.front();
        dq.pop_front();

        if (vis[b][id]) conts;
        vis[b][id] = 1;

        if (id == 1) {
            cout << cost << endl;
            return;
        }

        int p = a[id].ss;

        // if (b < n) {
        //     dummy[b].pb({b + n, 0});
        //     dummy[b + n].pb({b, id});
        // }

        // edges with weight = 0
        for (auto [b2, id2] : dummy[b]) {
            dq.push_front({cost, b2, id2});
        }

        // edges with weight = 1
        if (b < n) {
            if (b + p < n) dq.pb({cost + 1, b + p, id});
            if (b - p >= 0) dq.pb({cost + 1, b - p, id});
        }
    }

    cout << -1 << endl;
}

int main()
{
    fastio;

    int t = 1;
    // cin >> t;
    rep1(i, t) {
        solve(i);
    }

    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'void usaco(std::string)':
skyscraper.cpp:64:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |     freopen((filename + ".in").c_str(), "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:65:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   65 |     freopen((filename + ".out").c_str(), "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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