Submission #428867

#	Time	Username	Problem	Language	Result	Execution time	Memory
428867		wiwiho	Ideal city (IOI12_city)	C++14	32 / 100	1089 ms	2980 KiB

city

#include <bits/stdc++.h>

#define mp make_pair
#define F first
#define S second
#define eb emplace_back

using namespace std;

typedef long long ll;

using pii = pair<int, int>;

const ll MOD = 1000000000;

int n;
vector<vector<int>> g;

vector<pii> dir = {mp(1, 0), mp(0, 1), mp(-1, 0), mp(0, -1)};

ll bfs(int st){
    vector<ll> dis(n, -1);
    dis[st] = 0;
    queue<int> q;
    q.push(st);
    ll ans = 0;
    while(!q.empty()){
        int now = q.front();
        ans += dis[now];
        q.pop();
        for(int i : g[now]){
            if(dis[i] != -1) continue;
            dis[i] = dis[now] + 1;
            q.push(i);
        }
    }
    return ans;
}

int DistanceSum(int N, int *X, int *Y){
    n = N;
    g.resize(n);

    map<pii, int> city;
    for(int i = 0; i < n; i++){
        city[mp(X[i], Y[i])] = i;
    }

    for(int i = 0; i < n; i++){
        int x = X[i], y = Y[i];
        for(pii d : dir){
            int nx = x + d.F, ny = y + d.S;
            if(city.find(mp(nx,ny)) == city.end()) continue;
            g[i].eb(city[mp(nx,ny)]);
        }
    }
    
    ll ans = 0;
    for(int i = 0; i < n; i++) ans += bfs(i);
    return ans / 2 % MOD;
}

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