Submission #526581

#	Time	Username	Problem	Language	Result	Execution time	Memory
526581		Carmel_Ab1	City Mapping (NOI18_citymapping)	C++17	57 / 100	305 ms	27840 KiB

citymapping

/*
#pragma GCC target ("avx2")
#pragma GCC optimization ("O3")
#pragma GCC optimization ("unroll-loops")
 */
#include<bits/stdc++.h>
#include "citymapping.h"
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>

//using namespace __gnu_pbds;
using namespace std;

typedef long double ld;
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int>vi;
typedef vector<vector<int>>vvi;
typedef vector<ll>vl;
typedef vector<vl> vvl;
typedef pair<int,int>pi;
typedef pair<ll,ll> pl;
typedef vector<pl> vpl;
typedef vector<ld> vld;
typedef pair<ld,ld> pld;
typedef vector<pi> vpi;

//typedef tree<ll, null_type, less_equal<ll>,rb_tree_tag,tree_order_statistics_node_update> ordered_set;
template<typename T> ostream& operator<<(ostream& os, vector<T>& a){os<<"[";for(int i=0; i<ll(a.size()); i++){os << a[i] << ((i!=ll(a.size()-1)?" ":""));}os << "]\n"; return os;}

#define all(x) x.begin(),x.end()
#define YES out("YES")
#define NO out("NO")
#define out(x){cout << x << "\n"; return;}
#define outfl(x){cout << x << endl;return;}
#define GLHF ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL)
#define print(x){for(auto ait:x) cout << ait << " "; cout << "\n";}
#define pb push_back
#define umap unordered_map

template<typename T1, typename T2> istream& operator>>(istream& is, pair<T1, T2>& p){is >> p.first >> p.second;return is;}
template<typename T1, typename T2> ostream& operator<<(ostream& os, pair<T1, T2>& p){os <<"" << p.first << " " << p.second << ""; return os;}
void usaco(string taskname){
    string fin = taskname + ".in";
    string fout = taskname + ".out";
    const char* FIN = fin.c_str();
    const char* FOUT = fout.c_str();
    freopen(FIN, "r", stdin);
    freopen(FOUT, "w", stdout);
}
template<typename T>
void read(vector<T>& v){
    int n=v.size();
    for(int i=0; i<n; i++)
        cin >> v[i];
}
template<typename T>
vector<T>UNQ(vector<T>a){
    vector<T>ans;
    for(T t:a)
        if(ans.empty() || t!=ans.back())
            ans.push_back(t);
    return ans;
}



#include "citymapping.h"

vi par;
int get(int x){return par[x]=(x==par[x]?x:get(par[x]));}
void unite(int u,int v){par[get(u)]=get(v);}

void find_roads(int N, int Q, int A[], int B[], int W[]) {
    if(Q==5e5){
        vvl E;
        for(int i=1; i<=N; i++)
            for(int j=i+1; j<=N; j++)
                E.pb({get_distance(i,j),i,j});
        par.resize(N+1);
        for(int i=1; i<=N; i++)
            par[i]=i;
        sort(all(E));
        for(int i=0,j=0; j<N-1; i++) {
            if(get(E[i][1])==get(E[i][2]))continue;
            unite(E[i][1],E[i][2]);
            A[j] = E[i][1], B[j] = E[i][2], W[j] = E[i][0];
            j++;
        }
        return;
    }
    if(Q==12000) {
        ll L = 1, R = N, d = get_distance(1, N);

        for (int i = 2; i <= N; i++) {
            ll d1 = get_distance(L, i), d2 = get_distance(R, i);
            if (d1 > d)
                R = i, d = d1;
            if (d2 > d)
                L = i, d = d2;
        }

        vpl s;
        for (int i = 1; i <= N; i++)
            s.pb({get_distance(L, i), i});
        sort(all(s));

        for (int i = 1; i < N; i++) {
            A[i - 1] = s[i - 1].second;
            B[i - 1] = s[i].second;
            W[i - 1] = s[i].first - s[i - 1].first;
        }
        return;
    }

    vvl E;
    vl d1(N+1);
    for(int i=2; i<=N; i++)
        d1[i]= get_distance(1,i);
    priority_queue<vl,vvl,greater<vl>>pq;
    for(int i=2; i<=N; i++)
        pq.push({d1[i],i});

    vector<bool>done(N+1);
    done[1]=1;
    vi deg(N+1);

    while(pq.size()){
        vl v=pq.top();
        pq.pop();

        ll x=v[1],d=v[0];

        ll p=-1;
        for(int i=1; i<=N; i++){
            if(!done[i] || deg[i]==2)continue;

            if(d1[i]==d1[x]+ get_distance(x,i)){
                p=x;
                break;
            }
        }
        done[x]=1;
        deg[p]++;
        E.pb({d1[p]-d1[x],p,x});
    }



    for(int i=0; i<E.size(); i++)
        A[i]=E[i][1],B[i]=E[i][2],W[i]=E[i][0];
}

Compilation message (stderr)

citymapping.cpp: In function 'void find_roads(int, int, int*, int*, int*)':
citymapping.cpp:132:19: warning: unused variable 'd' [-Wunused-variable]
  132 |         ll x=v[1],d=v[0];
      |                   ^
citymapping.cpp:150:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::vector<long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  150 |     for(int i=0; i<E.size(); i++)
      |                  ~^~~~~~~~~
citymapping.cpp: In function 'void usaco(std::string)':
citymapping.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     freopen(FIN, "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~
citymapping.cpp:49:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   49 |     freopen(FOUT, "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 13 / 13
• Subtask 4: 19 / 19
• Subtask 5: 0 / 43