Submission #14408

#	Time	Username	Problem	Language	Result	Execution time	Memory
14408		gs14004	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	57 / 100	1000 ms	143176 KiB

skyscraper

#include <cstdio>
#include <cstdlib>
#include <vector>
#include <algorithm>
#include <utility>
#include <queue>
using namespace std;

int m, n;

int piv;
vector<int> dx[30005], label[30005];

bool r_dir[30005][180], l_dir[30005][180];
int px[30005], py[30005];

vector<int> graph[30005];
int *graph0, *graph1;
bool *vis;

queue<int> pq[2];

int dijkstra(int st, int ed){
    pq[0].push(st);
    int dist = 0;
    while (1) {
        if(pq[dist%2].empty()) break;
        while (!pq[dist%2].empty()) {
            int qf = pq[dist%2].front();
            pq[dist%2].pop();
            if(qf == ed){
                return dist;
            }
            if(vis[qf]) continue;
            vis[qf] = 1;
            if(qf < n){
                for (auto &i : graph[qf]){
                    if(!vis[i]){
                        pq[dist%2].push(i);
                    }
                }
            }
            if(qf >= n && graph0[qf] != 0 && !vis[graph0[qf] - 1]){
                pq[dist%2].push(graph0[qf] - 1);
            }
            if(qf >= n && graph1[qf] != 0 && !vis[graph1[qf]]){
                pq[(dist+1)%2].push(graph1[qf]);
            }
        }
        dist++;
    }
    return -1;
}

int main(){
    int st = 0, ed = 0;
    scanf("%d %d",&n,&m);
    for (int i=0; i<m; i++) {
        int x,y;
        scanf("%d %d",&x,&y);
        px[i] = x;
        py[i] = y;
        if(i == 0){
            st = x;
        }
        else if(i == 1){
            ed = x;
        }
        if(y < 180){
            r_dir[x][y] = 1;
            l_dir[x][y] = 1;
        }
        else{
            for (int j=0; j * y + x < n; j++) {
                dx[j * y + x].push_back(y);
            }
            for (int j=0; j * y + x >= 0; j--) {
                dx[j * y + x].push_back(-y);
            }
        }
    }
    for (int i=1; i<180; i++) {
        for (int j=i; j<n; j++) {
            r_dir[j][i] |= r_dir[j - i][i];
        }
        for (int j=n-i-1; j>=0; j--) {
            l_dir[j][i] |= l_dir[j + i][i];
        }
        for (int j=0; j<n; j++) {
            if(r_dir[j][i]){
                dx[j].push_back(i);
            }
            if(l_dir[j][i]){
                dx[j].push_back(-i);
            }
        }
    }
    piv = n;
    for (int i=0; i<n; i++) {
        sort(dx[i].begin(),dx[i].end());
        dx[i].resize(unique(dx[i].begin(),dx[i].end()) - dx[i].begin());
        for (auto &j : dx[i]){
            label[i].push_back(piv++);
        }
    }
    graph0 = (int*) calloc(piv,sizeof(int));
    graph1 = (int*) calloc(piv,sizeof(int));
    vis = (bool*) calloc(piv,sizeof(bool));
    for(int t=0; t<m; t++){
        int i = px[t];
        int j = py[t];
        int pos = (int)(lower_bound(dx[i].begin(),dx[i].end(),j) - dx[i].begin());
        if(pos != dx[i].size() && dx[i][pos] == j){
            graph[i].push_back(label[i][pos]);
        }
        pos = (int)(lower_bound(dx[i].begin(),dx[i].end(),-j) - dx[i].begin());
        if(pos != dx[i].size() && dx[i][pos] == -j){
            graph[i].push_back(label[i][pos]);
        }
    }
    int piv = n;
    for (int i=0; i<n; i++){
        for (int j=0; j<dx[i].size(); j++) {
            int tmp_first = i;
            int tmp_second = dx[i][j];
            graph0[piv++] = i+1;
            if(tmp_first + tmp_second < 0 || tmp_first + tmp_second >= n) continue;
            tmp_first += tmp_second;
            int pos = (int)(lower_bound(dx[tmp_first].begin(),dx[tmp_first].end(),tmp_second)
                            - dx[tmp_first].begin());
            if(pos == dx[tmp_first].size() || dx[tmp_first][pos] != tmp_second) continue;
            graph1[piv - 1] = label[tmp_first][pos];
        }
    }
    printf("%d\n",dijkstra(st,ed));
}

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