Submission #1256236

#	Time	Username	Problem	Language	Result	Execution time	Memory
1256236		nanaseyuzuki	Jakarta Skyscrapers (APIO15_skyscraper)	C++20	57 / 100	156 ms	237448 KiB

skyscraper

#include <bits/stdc++.h>
/*
    --> Author: Kazuki_Hoshino__8703 <--
    I love Nanasaki Ai ☆*: .。. o(≒＿≒)o .。.:☆
*/
#define fi first
#define se second
#define pii pair<int, int>
#define ll long long
using namespace std;

const int mn = 3e4 + 5, bm = (1 << 11) + 1, mod = 1532023, offset = 5e4;
const int inf = 1e9, base = 311;

int n, m, a[mn], b[mn];
int d[mn][2005];
vector <int> speed[mn];

void dijkstra(){
    queue<pair<int, pii>> pq;
    fill(&d[0][0], &d[0][0] + mn * 2005, inf);
    d[a[0]][b[0]] = 0;
    pq.push({d[a[0]][b[0]], {a[0], b[0]}});
    while(pq.size()){
        auto[c, i] = pq.front();
        auto[u, sp] = i;
        pq.pop();
        if(c > d[u][sp]) continue;
        if(u + sp < n && d[u + sp][sp] > d[u][sp] + 1){
            d[u + sp][sp] = d[u][sp] + 1;
            pq.push({d[u + sp][sp], {u + sp, sp}});
        }
        if(u - sp >= 0 && d[u - sp][sp] > d[u][sp] + 1){
            d[u - sp][sp] = d[u][sp] + 1;
            pq.push({d[u - sp][sp], {u - sp, sp}});
        }
        for(auto qq : speed[u]){
            if(d[u][qq] > d[u][sp]){
                d[u][qq] = d[u][sp];
                pq.push({d[u][qq], {u, qq}});
            }
        }
    }
    int res = inf;
    for(int sp = 0; sp <= 2000; sp++) res = min(res, d[a[1]][sp]);
    if(res == inf) res = -1;
    cout << res << '\n';
}

void solve(){
    cin >> n >> m;
    for(int i = 0; i < m; i++){
        cin >> a[i] >> b[i];
        speed[a[i]].push_back(b[i]);
    }
    dijkstra();
}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    if(fopen("ROBOT.INP", "r")) {
        freopen("ROBOT.INP", "r", stdin);
        freopen("ROBOT.OUT", "w", stdout);
    }
    int t = 1;
    // cin >> t;
    while(t--) {
        solve();
    }
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:63:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   63 |         freopen("ROBOT.INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:64:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   64 |         freopen("ROBOT.OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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