Submission #678064

#	Time	Username	Problem	Language	Result	Execution time	Memory
678064		Cross_Ratio	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	992 ms	3980 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;
const int INF = 1e9;
int B[30005];
int C[30005];
int dis[30005];
bool vis[30005];
vector<int> V[30005];
typedef pair<int,int> P;
signed main() {
    cin.sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    int N, M;
    cin >> N >> M;
    clock_t st = clock();
    int i, j;
    for(i=0;i<M;i++) cin >> B[i] >> C[i];
    for(i=0;i<N;i++) dis[i] = INF;
    for(i=0;i<M;i++) V[B[i]].push_back(i);
    dis[B[0]] = 0;
    priority_queue<P,vector<P>,greater<P>> PQ;
    PQ.push(P(0,B[0]));
    while(!PQ.empty()) {
        if(clock() - st >= 990000) break;
        P k2 = PQ.top();
        PQ.pop();
        int id = k2.second;
        if(vis[id]) continue;
        vis[id] = true;
        set<int> S;
        for(int k : V[id]) {
            if(S.find(C[k])!=S.end()) continue;
            S.insert(C[k]);
            int st = B[k] % C[k];
            assert(B[k]==id);
            for(i=st;i<N;i+=C[k]) {
                int d = abs(i - B[k]) / C[k];
                if(dis[i] > dis[id] + d) {
                    dis[i] = dis[id] + d;
                    PQ.push(P(dis[i], i));
                }
            }
        }
    }
    cout << (dis[B[1]]==INF?-1:dis[B[1]]);
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:17:12: warning: unused variable 'j' [-Wunused-variable]
   17 |     int i, j;
      |            ^

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