Submission #568135

#	Time	Username	Problem	Language	Result	Execution time	Memory
568135		benjaminkleyn	Ideal city (IOI12_city)	C++17	32 / 100	877 ms	19856 KiB

city

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

map<pair<int,int>, bool> exists;
map<pair<int,int>, int> node_of;
int sz[100000];
int sub_sz[100000];
bool vis[100000];

int dfs(pair<int,int> u)
{
    int cur_node = node_of[u];
    vis[cur_node] = true;
    int cur_x = u.first;
    sub_sz[cur_node] = sz[cur_node];
    while (exists[{++cur_x, u.second}] == true)
    {
        if (exists[{cur_x, u.second - 1}] == true && !vis[node_of[{cur_x, u.second - 1}]])
                sub_sz[cur_node] += dfs({cur_x, u.second - 1});
                
        if (exists[{cur_x, u.second + 1}] == true && !vis[node_of[{cur_x, u.second + 1}]])
                sub_sz[cur_node] += dfs({cur_x, u.second + 1});
    }
    cur_x = u.first + 1;
    while (exists[{--cur_x, u.second}] == true)
    {
        if (exists[{cur_x, u.second - 1}] == true && !vis[node_of[{cur_x, u.second - 1}]])
                sub_sz[cur_node] += dfs({cur_x, u.second - 1});
                
        if (exists[{cur_x, u.second + 1}] == true && !vis[node_of[{cur_x, u.second + 1}]])
                sub_sz[cur_node] += dfs({cur_x, u.second + 1});
    }
    return sub_sz[cur_node];
}

int solve(int N, int *X, int *Y)
{
    exists.clear();
    node_of.clear();
    for (int i = 0; i < N; i++)
        exists[{X[i], Y[i]}] = true;

    int node = 0;
    for (int i = 0; i < N; i++)
    {
        if (node_of[{X[i], Y[i]}] != 0) continue;

        node_of[{X[i], Y[i]}] = ++node;

        int cur_x = X[i];
        while (exists[{--cur_x, Y[i]}] == true)
            node_of[{cur_x, Y[i]}] = node;
        cur_x = X[i];
        while (exists[{++cur_x, Y[i]}] == true)
            node_of[{cur_x, Y[i]}] = node;
    }

    for (int i = 1; i <= node; i++)
        sz[i] = sub_sz[i] = vis[i] = 0;

    for (int i = 0; i < N; i++)
        sz[node_of[{X[i], Y[i]}]]++;

    dfs({X[0], Y[0]});
    ll res = 0;    
    for (int i = 2; i <= node; i++)
        res += sub_sz[i] * (N - sub_sz[i]) % 1'000'000'000, res %= 1'000'000'000;

    return (int) res;
}

int DistanceSum(int N, int *X, int *Y) 
{
    return (solve(N, X, Y) + solve(N, Y, X)) % 1'000'000'000;
}

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