Submission #856636

#	Time	Username	Problem	Language	Result	Execution time	Memory
856636		hariaakas646	Jakarta Skyscrapers (APIO15_skyscraper)	C++17	0 / 100	1 ms	424 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

#define scd(t) scanf("%d", &t)
#define sclld(t) scanf("%lld", &t)
#define forr(i, j, k) for (int i = j; i < k; i++)
#define frange(i, j) forr(i, 0, j)
#define all(cont) cont.begin(), cont.end()
#define mp make_pair
#define pb push_back
#define f first
#define s second
typedef long long int lli;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<bool> vb;
typedef vector<lli> vll;
typedef vector<string> vs;
typedef vector<pii> vii;
typedef vector<vi> vvi;
typedef map<int, int> mpii;
typedef set<int> seti;
typedef multiset<int> mseti;
typedef long double ld;


void usaco()
{
    freopen("/media/hariaakash646/785EF1075EF0BF46/CompetitiveProgramming/input.in", "r", stdin);
//    freopen("problem.out", "w", stdout);
}

int main() {
    // usaco();
    int n, m;
    scd(n);
    scd(m);

    int sq = sqrt(n);

    vector<vii> graph(n);
    vector<vb> con(n, vb(sq));

    int st;
    int en;
    
    frange(i, m) {
        int b, p;
        scd(b);
        scd(p);
        if(i == 0) st = b;
        if(i == 1) en = b;
        if(p >= sq) {
            for(int i=1; b+i*p<n; i++) {
                graph[b].pb(mp(b+i*p, i));
                // printf("%d %d %d\n", b, b+i*p, i);
            }
            for(int i=1; b-i*p>=0; i++) {
                graph[b].pb(mp(b-i*p, i));
                // printf("%d %d %d\n", b, b-i*p, i);
            }
        }
        else {
            con[b][p] = true;
        }
    }

    // forr(p, 1, sq) {
    //     vb vis(n);
    //     queue<int> q;
    //     frange(i, n) {
    //         if(con[i][p]) q.push(i);
    //     }
    //     while(q.size()) {
    //         auto x = q.front();
    //         q.pop();
    //         if(vis[x]) continue;
    //         vis[x] = true;
    //         if(x + p < n) {
    //             graph[x].pb(mp(x+p, 1));
    //             q.push(x+p);
    //             printf("%d %d %d\n", x, x+p, 1);
    //         }
    //         if(x - p >= 0) {
    //             graph[x].pb(mp(x-p, 1));
    //             q.push(x-p);
    //             printf("%d %d %d\n", x, x-p, 1);
    //         }
    //     }
    // }

    vector<vb> vis(n, vb(sq));
    vvi dist(n, vi(sq, 2e9));
    dist[st][0] = 0;
    forr(i, 1, sq) {
        if(con[st][i]) dist[st][i] = 0;
    }
    priority_queue<pair<int, pii>> pq;
    pq.push(mp(0, mp(st, 0)));

    while(pq.size()) {
        auto p = pq.top();
        pq.pop();
        if(vis[p.s.f][p.s.s]) continue;
        vis[p.s.f][p.s.s] = true;
        dist[p.s.f][0] = min(dist[p.s.f][0], dist[p.s.f][p.s.s]);
        for(auto e : graph[p.s.s]) {
            if(-p.f + e.s < dist[e.f][0]) {
                dist[e.f][0] = -p.f + e.s;
                pq.push(mp(-dist[e.f][0], mp(e.f, 0)));
            }
        }
        
        if(p.s.s) {
            if(p.s.f + p.s.s < n && -p.f + 1 < dist[p.s.f + p.s.s][p.s.s]) {
                dist[p.s.f + p.s.s][p.s.s] = -p.f + 1;
                pq.push(mp(-dist[p.s.f + p.s.s][p.s.s], mp(p.s.f + p.s.s, p.s.s)));
            }
            if(p.s.f - p.s.s >= 0 && -p.f + 1 < dist[p.s.f - p.s.s][p.s.s]) {
                dist[p.s.f - p.s.s][p.s.s] = -p.f + 1;
                pq.push(mp(-dist[p.s.f - p.s.s][p.s.s], mp(p.s.f - p.s.s, p.s.s)));
            }
        }
        forr(i, 1, sq) {
            if(con[p.s.f][i]) {
                if(p.s.f + i < n && -p.f + 1 < dist[p.s.f + i][i]) {
                    dist[p.s.f + i][i] = -p.f + 1;
                    pq.push(mp(-dist[p.s.f + i][i], mp(p.s.f + i, i)));
                }
                if(p.s.f - i >= 0 && -p.f + 1 < dist[p.s.f - i][i]) {
                    dist[p.s.f - i][i] = -p.f + 1;
                    pq.push(mp(-dist[p.s.f - i][i], mp(p.s.f - i, i)));
                }
            }
        }
    }
    int mi = 2e9;
    frange(i, sq) mi = min(mi, dist[en][i]);
    if(mi < 2e9) printf("%d", mi);
    else printf("-1");


}

Compilation message (stderr)

skyscraper.cpp: In function 'void usaco()':
skyscraper.cpp:30:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   30 |     freopen("/media/hariaakash646/785EF1075EF0BF46/CompetitiveProgramming/input.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:5:21: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | #define scd(t) scanf("%d", &t)
      |                ~~~~~^~~~~~~~~~
skyscraper.cpp:37:5: note: in expansion of macro 'scd'
   37 |     scd(n);
      |     ^~~
skyscraper.cpp:5:21: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | #define scd(t) scanf("%d", &t)
      |                ~~~~~^~~~~~~~~~
skyscraper.cpp:38:5: note: in expansion of macro 'scd'
   38 |     scd(m);
      |     ^~~
skyscraper.cpp:5:21: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | #define scd(t) scanf("%d", &t)
      |                ~~~~~^~~~~~~~~~
skyscraper.cpp:50:9: note: in expansion of macro 'scd'
   50 |         scd(b);
      |         ^~~
skyscraper.cpp:5:21: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    5 | #define scd(t) scanf("%d", &t)
      |                ~~~~~^~~~~~~~~~
skyscraper.cpp:51:9: note: in expansion of macro 'scd'
   51 |         scd(p);
      |         ^~~
skyscraper.cpp:100:28: warning: 'st' may be used uninitialized in this function [-Wmaybe-uninitialized]
  100 |     pq.push(mp(0, mp(st, 0)));
      |                            ^
skyscraper.cpp:139:39: warning: 'en' may be used uninitialized in this function [-Wmaybe-uninitialized]
  139 |     frange(i, sq) mi = min(mi, dist[en][i]);
      |                                       ^

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