Submission #363044

#	Time	Username	Problem	Language	Result	Execution time	Memory
363044		eric_xiao	Ideal city (IOI12_city)	C++14	11 / 100	1090 ms	5308 KiB

city

#include<bits/stdc++.h>
#define ll long long
#define pll pair<int,int>
#define F first
#define S second
using namespace std;
const ll m = 1000000000;
struct hash_pair {
    template <class T1, class T2>
    size_t operator()(const pair<T1, T2>& p) const
    {
        auto hash1 = hash<T1>{}(p.first);
        auto hash2 = hash<T2>{}(p.second);
        return hash1 ^ hash2;
    }
};
unordered_set<pll,hash_pair> st;
unordered_map<pll,ll,hash_pair> dis;
pll all[100009];
ll X[4] = {0,1,0,-1},Y[4] {1,0,-1,0};
/*k = 0 U
  k = 1 R
  k = 2 D
  k = 4 L*/
ll ans;
void BFS(pll s)
{
    queue<pll> q;
    q.push(s);
    ll i;
    dis.clear();
    dis[s] = 0;
    while(!q.empty())
    {
        auto u = q.front();
        q.pop();
        for(i = 0;i < 4;i++)
        {
            if(st.count({u.F + X[i],u.S + Y[i]}) && !dis.count({u.F + X[i],u.S + Y[i]}))
            {
                dis[{u.F + X[i],u.S + Y[i]}] = dis[u] + 1;
                q.push({u.F + X[i],u.S + Y[i]});
            }
        }
    }
    for(auto a : dis)
    {
        ans += a.S;
    }
}
int DistanceSum(int N, int *X, int *Y) {
    ll M,i,j,k;
    st.reserve(2048);
    st.max_load_factor(0.25);
    dis.reserve(2048);
    dis.max_load_factor(0.25);
    for(i = 0;i < N;i++)
    {
        all[i] = {X[i],Y[i]};
    }
    sort(all,all+N);
    for(i = N-1;i >= 0;i--)
    {
        st.insert(all[i]);
    }
    for(i = 0;i < N;i++)
    {
        BFS(all[i]);
    }
    return (int)(ans/2)%m;
}

Compilation message (stderr)

city.cpp: In function 'int DistanceSum(int, int*, int*)':
city.cpp:52:8: warning: unused variable 'M' [-Wunused-variable]
   52 |     ll M,i,j,k;
      |        ^
city.cpp:52:12: warning: unused variable 'j' [-Wunused-variable]
   52 |     ll M,i,j,k;
      |            ^
city.cpp:52:14: warning: unused variable 'k' [-Wunused-variable]
   52 |     ll M,i,j,k;
      |              ^

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