Submission #52654

#	Time	Username	Problem	Language	Result	Execution time	Memory
52654		evpipis	Jakarta Skyscrapers (APIO15_skyscraper)	C++11	100 / 100	321 ms	45132 KiB

skyscraper

#include <bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pb push_back
#define mp make_pair
typedef pair<int, int> ii;

const int len = 30005, inf = 1e9;
int po[len], pos[len], vis[len], dis[len][180][2];
vector<int> vec[len];
//map<int, int> mymap[len];
deque<pair<ii, ii> > deq;

int main(){
    int n, m, k;
    scanf("%d %d", &n, &m);
    k = sqrt(n)+1;
    for (int i = 0; i < m; i++)
        scanf("%d %d", &pos[i], &po[i]);
    for (int i = 0; i < m; i++)
        vec[pos[i]].pb(po[i]);

    for (int i = 0; i < n; i++)
        for (int j = 0; j <= k; j++)
            dis[i][j][0] = dis[i][j][1] = inf;

    int ans = -1;
    deq.pb(mp(mp(0, 0), mp(pos[0], po[0])));
    deq.pb(mp(mp(0, 1), mp(pos[0], po[0])));
    while (!deq.empty()){
        pair<ii, ii> top = deq.front();
        deq.pop_front();

        int d = top.fi.fi, t = top.fi.se, b = top.se.fi, p = top.se.se;
        if (b == pos[1]){
            ans = d;
            break;
        }

        //if (mymap[b].count(p)) continue;
        //mymap[b][p] = d;
        if (p <= k && dis[b][p][t] != inf)
            continue;
        if (p <= k)
            dis[b][p][t] = d;

        if (t == 0 && b-p >= 0)
            deq.pb(mp(mp(d+1, t), mp(b-p, p)));
        if (t == 1 && b+p < n)
            deq.pb(mp(mp(d+1, t), mp(b+p, p)));

        if (vis[b]) continue;
        vis[b] = 1;
        for (int j = 0; j < vec[b].size(); j++){
            deq.push_front(mp(mp(d, 0), mp(b, vec[b][j])));
            deq.push_front(mp(mp(d, 1), mp(b, vec[b][j])));
        }
    }

    printf("%d\n", ans);
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:56:27: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for (int j = 0; j < vec[b].size(); j++){
                         ~~^~~~~~~~~~~~~~~
skyscraper.cpp:18:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp:21:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &pos[i], &po[i]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

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