Submission #592865

#	Time	Username	Problem	Language	Result	Execution time	Memory
592865		skittles1412	Ideal city (IOI12_city)	C++17	32 / 100	1092 ms	3448 KiB

city

#include "bits/extc++.h"

using namespace std;

template <typename T>
void dbgh(const T& t) {
    cerr << t << endl;
}

template <typename T, typename... U>
void dbgh(const T& t, const U&... u) {
    cerr << t << " | ";
    dbgh(u...);
}

#ifdef DEBUG
#define dbg(...)                                              \
    cerr << "L" << __LINE__ << " [" << #__VA_ARGS__ << "]: "; \
    dbgh(__VA_ARGS__);
#else
#define dbg(...)
#define cerr   \
    if (false) \
    cerr
#endif

#define endl "\n"
#define long int64_t
#define sz(x) int((x).size())

const long mod = 1e9;
const int dx[] = {-1, 1, 0, 0}, dy[] = {0, 0, -1, 1};

int bf(int n, int* arrx, int* arry) {
    map<pair<int, int>, int> m;
    for (int i = 0; i < n; i++) {
        m[{arrx[i], arry[i]}] = i;
    }
    vector<int> graph[n];
    for (int i = 0; i < n; i++) {
        int x = arrx[i], y = arry[i];
        for (int k = 0; k < 4; k++) {
            auto it = m.find({x + dx[k], y + dy[k]});
            if (it != m.end()) {
                int u = it->second;
                graph[i].push_back(u);
                graph[u].push_back(i);
            }
        }
    }
    long ans = 0;
    for (int i = 0; i < n; i++) {
        int dist[n];
        memset(dist, -1, sizeof(dist));
        queue<int> q;
        auto push = [&](int u, int d) -> void {
            if (dist[u] == -1) {
                dist[u] = d;
                q.push(u);
            }
        };
        push(i, 0);
        while (sz(q)) {
            int u = q.front();
            q.pop();
            for (auto& v : graph[u]) {
                push(v, dist[u] + 1);
            }
        }
        ans += accumulate(dist, dist + n, 0);
    }
    return ans / 2 % mod;
}

int DistanceSum(int n, int *arrx, int *arry) {
    if (n <= 2000) {
        return bf(n, arrx, arry);
    }
}

Compilation message (stderr)

city.cpp: In function 'int DistanceSum(int, int*, int*)':
city.cpp:79:1: warning: control reaches end of non-void function [-Wreturn-type]
   79 | }
      | ^

• Subtask 1: 11 / 11
• Subtask 2: 21 / 21
• Subtask 3: 0 / 23
• Subtask 4: 0 / 45