Submission #670240

#	Time	Username	Problem	Language	Result	Execution time	Memory
670240		1bin	Ideal city (IOI12_city)	C++14	100 / 100	58 ms	10056 KiB

city

#include <bits/stdc++.h>

using namespace std;

#define all(v) v.begin(), v.end()
typedef long long ll;
const int NMAX = 1e5 + 5;
const ll mod = 1e9;
int n, X[NMAX], Y[NMAX], a[NMAX], w[NMAX];
vector<pair<int, int>> v;
vector<int> adj[NMAX];

ll dfs(int x, int p){
    ll ret = 0;
    for(int& nx : adj[x]){
        if(nx == p) continue;
        ret += dfs(nx, x);
        ret += 1LL * w[nx] * (n - w[nx]); ret %= mod;
        w[x] += w[nx];
    }
    return ret;
}

ll go(){
    sort(all(v));
    ll by = -1, bx = -1, t = 0;
    for(int i = 0; i < n; i++){
        auto&[x, y] = v[i];
        if(bx == x && y == by + 1) a[i] = a[i - 1];
        else a[i] = ++t;
        w[a[i]]++;
        int j = lower_bound(all(v), make_pair(x - 1, y)) - v.begin();
        if(v[j] == make_pair(x - 1, y)) {
            adj[a[j]].emplace_back(a[i]);
            adj[a[i]].emplace_back(a[j]);
        }
        by = y; bx = x;
    }
    for(int i = 1; i <= t; i++) adj[i].erase(unique(all(adj[i])), adj[i].end());
    ll ret = dfs(1, -1);
    for(int i = 1; i <= t; i++) adj[i].clear(), w[i] = 0;
    return ret;
}

int DistanceSum(int n_, int* X, int* Y){
    ll ret = 0; n = n_;
    for(int i = 0; i < n; i++) v.emplace_back(X[i], Y[i]);
    ret = go();
    
    for(int i = 0; i < n; i++) swap(v[i].first, v[i].second);
    ret += go(); ret %= mod;
    return ret;
}

/*
int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    
    cin >> n;
    for(int i = 0; i < n; i++) cin >> X[i] >> Y[i];
    cout << DistanceSum(n, X, Y);
    return 0;
}*/

Compilation message (stderr)

city.cpp: In function 'll go()':
city.cpp:28:14: warning: structured bindings only available with '-std=c++17' or '-std=gnu++17'
   28 |         auto&[x, y] = v[i];
      |              ^

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