Submission #1253980

#	Time	Username	Problem	Language	Result	Execution time	Memory
1253980		hoa208	Jakarta Skyscrapers (APIO15_skyscraper)	C++20	100 / 100	64 ms	24512 KiB

skyscraper

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, b, a) for (int i = (b), _a = (a); i >= _a; i--)
#define pa pair<ll, ll>
#define fi first
#define se second
#define bit(mask, j) ((mask >> j) & 1)
#define t_test int t;cin >> t;while(t--)
const   ll mod = 1e9 + 7;
const   ll INF = 1e18;
inline  void adm(ll &x){if(x>=mod)x%=mod;else if(x<0)x+=mod;}
//--------------------------------------------------------------------

struct state {
    int w, u;
    bool operator < (const state &a) const {
        return w > a.w;
    }
};
priority_queue<state> q;
const int BLOCK = 177;
const int N = 3e4 + 10;
vector<int> g[N];
int n, m;
int dp[N], mark[N][BLOCK + 2];
void hbmt() {
    cin >> n >> m;
    int doge1 = 0;
    memset(dp, 0x3f, sizeof dp);
    FOR(i, 1, m) {
        int b, p;
        cin >> b >> p;
        if(i == 1) {
            dp[b] = 0;
            q.push({0, b});
        }
        if(i == 2) {
            doge1 = b;
        }
        g[b].push_back(p);
    }
    while(!q.empty()) {
        int u = q.top().u, du = q.top().w;
        q.pop();
        if(du != dp[u]) continue;
        if(u == doge1) {
            cout << du;
            exit(0);
        }
        for(auto p : g[u]) {
            int c = 0;
            for(int v = u + p; v < n; v += p) {
                c++;
                if(dp[v] > dp[u] + c) {
                    dp[v] = dp[u] + c;
                    q.push({dp[v], v});
                }
                if(p <= BLOCK && mark[v][p]) break;
                if(p <= BLOCK) {
                    mark[v][p] = true;
                }
            }
            c = 0;
            for(int v = u - p; v >= 0; v -= p) {
                c++;
                if(dp[v] > dp[u] + c) {
                    dp[v] = dp[u] + c;
                    q.push({dp[v], v});
                }
                if(p <= BLOCK && mark[v][p]) break;
                if(p <= BLOCK) {
                    mark[v][p] = true;
                }
            }
        }
    }
    cout << -1;
}

int main() {
    
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    
    if(fopen("hbmt.inp", "r")) {
        freopen("hbmt.inp", "r", stdin);
        freopen("hbmt.out", "w", stdout);
    }
    
    // t_test 
    hbmt();
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:88:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   88 |         freopen("hbmt.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen("hbmt.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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