Submission #52630

#	Time	Username	Problem	Language	Result	Execution time	Memory
52630		chpipis	Jakarta Skyscrapers (APIO15_skyscraper)	C++11	57 / 100	1088 ms	25328 KiB

skyscraper

#include <bits/stdc++.h>

using namespace std;

#define fi first
#define se second
#define mp make_pair
#define pb push_back
#define pf push_front
#define iter(v, i) for (__typeof__((v).begin()) i = (v).begin(); i != (v).end(); i++)
#define fast_io_without_cstdio ios_base::sync_with_stdio(false), cin.tie(NULL)
#define all(v) (v).begin(), (v).end()
#define rep(i, s, e) for (int i = s; i < e; i++)

// START for segment tree
#define params int p, int L, int R
#define housekeep int mid = (L + R) >> 1, left = p << 1, right = left | 1
// END

#ifdef __linux__
#define gc getchar_unlocked
#define pc putchar_unlocked
#else
#define gc getchar
#define pc putchar
#endif

#if __cplusplus <= 199711L
template<class BidirIt>
BidirIt prev(BidirIt it, typename iterator_traits<BidirIt>::difference_type n = 1) {
    advance(it, -n);
    return it;
}

template<class ForwardIt>
ForwardIt next(ForwardIt it, typename iterator_traits<ForwardIt>::difference_type n = 1) {
    advance(it, n);
    return it;
}
#endif

typedef long long ll;
typedef pair<int, int> ii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef long double ldouble;

const double EPS = 1e-9;
const double PI = 3.141592653589793238462;

template<typename T>
inline T sq(T a) { return a * a; }

//#ifdef LOCAL_MACHINE
//#endif

const int SIZE = 175;
const int MAXN = 3e4 + 5;
const int INF = 1e9;

int dist[MAXN][SIZE];
priority_queue<pair<int, ii>, vector<pair<int, ii> >, greater<pair<int, ii> > > pq;
vi vec[MAXN];

void relax(int i, int x, int d) {
    if (dist[i][x] <= d) return;
    dist[i][x] = d;
    pq.push(mp(d, mp(i, x)));
}

int main() {
    //freopen("", "r", stdin);
    //freopen("", "w", stdout);
    int n, m, st = -1, en = -1;
    scanf("%d %d", &n, &m);
    for (int i = 0; i < m; i++) {
        int b, p;
        scanf("%d %d", &b, &p);
        vec[b].pb(p);
        if (i == 0) st = b;
        if (i == 1) en = b;
    }
    for (int i = 0; i <= n; i++)
        for (int j = 0; j < SIZE; j++)
            dist[i][j] = INF;
    dist[st][0] = 0;
    pq.push(mp(0, mp(st, 0)));
    int ans = INF;
    while (!pq.empty()) {
        int w = pq.top().fi;
        int u = pq.top().se.fi;
        int x = pq.top().se.se;
        pq.pop();

        if (u == en) {
            ans = min(ans, w);
            continue;
        }
        if (w >= ans) continue;
        if (dist[u][x] < w) continue;

        if (x == 0) {
            for (auto it : vec[u]) {
                if (it < SIZE) {
                    relax(u, it, w);
                } else {
                    for (int v = u + it; v < n; v += it) {
                        relax(v, 0, w + (v - u) / it);
                    }
                    for (int v = u - it; v >= 0; v -= it) {
                        relax(v, 0, w + (u - v) / it);
                    }
                }
            }
        } else {
            relax(u, 0, w);
            if (u + x < n)
                relax(u + x, x, w + 1);
            if (u - x >= 0)
                relax(u - x, x, w + 1);
        }
    }
    //int ans = *min_element(dist[en], dist[en] + SIZE);
    if (ans == INF)
        puts("-1");
    else
        printf("%d\n", ans);
    return 0;
}

Compilation message (stderr)

skyscraper.cpp: In function 'int main()':
skyscraper.cpp:75:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d %d", &n, &m);
     ~~~~~^~~~~~~~~~~~~~~~~
skyscraper.cpp:78:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d %d", &b, &p);
         ~~~~~^~~~~~~~~~~~~~~~~

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