Submission #1073879

#	Time	Username	Problem	Language	Result	Execution time	Memory
1073879		RiverFlow	Jakarta Skyscrapers (APIO15_skyscraper)	C++14	100 / 100	897 ms	3792 KiB

skyscraper

#include <bits/stdc++.h>

#define nl "\n"
#define no "NO"
#define yes "YES"
#define fi first
#define se second
#define vec vector
#define task "main"
#define _mp make_pair
#define ii pair<int, int>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#define evoid(val) return void(std::cout << val)
#define FOR(i, a, b) for(int i = (a); i <= (b); ++i)
#define FOD(i, b, a) for(int i = (b); i >= (a); --i)
#define unq(x) sort(all(x)); x.resize(unique(all(x)) - x.begin())

using namespace std;

template<typename U, typename V> bool maxi(U &a, V b) {
    if (a < b) { a = b; return 1; } return 0;
}
template<typename U, typename V> bool mini(U &a, V b) {
    if (a > b) { a = b; return 1; } return 0;
}

const int N = (int)3e4 + 9;
const int mod = (int)1e9 + 7;

void prepare(); void main_code();

int main() {
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    const bool MULTITEST = 0; prepare();
    int num_test = 1; if (MULTITEST) cin >> num_test;
    while (num_test--) { main_code(); }
}

void prepare() {};

int dis[N];

vector<int> g[N];

void main_code() {
    int n, m;
    cin >> m >> n;
    int p0 = 0, pos = 0, ed = 0;
    for(int i = 0; i < n; ++i) {
        int b, p; cin >> b >> p;
        if (i == 0) {
            p0 = p;
            pos = b;
            g[pos].push_back(p);
        } else if (i == 1) {
            ed = b;
        } else {
            g[b].push_back(p);
        }
    }
    FOR(i, 0, m - 1) dis[i] = -1;
    // (0, m - 1)
    priority_queue<ii, vec<ii>, greater<ii>> pq;
    pq.push(_mp(0, pos)); dis[pos] = 0;

    while (!pq.empty()) {
        auto x = pq.top(); pq.pop();
        int u = x.second;
        if (dis[u] != x.fi) continue ;
        if (u == ed) break ;
        for(int v : g[u]) {
            for(int k = u - v, c = 1; k >= 0; k -= v, ++c) {
                if (dis[k] == -1 or dis[k] > dis[u] + c) {
                    dis[k] = dis[u] + c;
                    pq.push(_mp(dis[k], k));
                }
            }
            for(int k = u + v, c = 1; k < m; k += v, ++c) {
                if (dis[k] == -1 or dis[k] > dis[u] + c) {
                    dis[k] = dis[u] + c;
                    pq.push(_mp(dis[k], k));
                }
            }
        }
    }
    cout << dis[ed];
}


/*     Let the river flows naturally     */

Compilation message (stderr)

skyscraper.cpp: In function 'void main_code()':
skyscraper.cpp:53:9: warning: variable 'p0' set but not used [-Wunused-but-set-variable]
   53 |     int p0 = 0, pos = 0, ed = 0;
      |         ^~
skyscraper.cpp: In function 'int main()':
skyscraper.cpp:36:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   36 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
skyscraper.cpp:37:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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