Submission #424674

#	Time	Username	Problem	Language	Result	Execution time	Memory
424674		MarcoMeijer	Towns (IOI15_towns)	C++14	100 / 100	23 ms	932 KiB

towns

#include "towns.h"
#include <bits/stdc++.h>
using namespace std;

// macros
typedef long long ll;
typedef long double ld;
typedef pair<int, int> ii;
typedef pair<ll, ll> lll;
typedef tuple<int, int, int> iii;
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<iii> viii;
typedef vector<ll> vll;
typedef vector<lll> vlll;
#define REP(a,b,c) for(int a=int(b); a<int(c); a++)
#define RE(a,c) REP(a,0,c)
#define RE1(a,c) REP(a,1,c+1)
#define REI(a,b,c) REP(a,b,c+1)
#define REV(a,b,c) for(int a=int(c-1); a>=int(b); a--)
#define FOR(a,b) for(auto& a : b)
#define all(a) a.begin(), a.end()
#define INF 1e9
#define EPS 1e-9
#define pb push_back
#define popb pop_back
#define fi first
#define se second
#define sz size()
mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

// output
template<class T1, class T2> void OUT(const pair<T1,T2>& x);
template<class T> void OUT(const vector<T>& x);
template<class T> void OUT(const T& x) {cerr << x;}
template<class H, class... T> void OUT(const H& h, const T&... t) {OUT(h); OUT(t...); }
template<class T1, class T2> void OUT(const pair<T1,T2>& x) {OUT(x.fi,' ',x.se);}
template<class T> void OUT(const vector<T>& x) {RE(i,x.size()) OUT(i==0?"":" ",x[i]);}
template<class... T> void OUTL(const T&... t) {OUT(t..., "\n"); }
template<class H> void OUTLS(const H& h) {OUTL(h); }
template<class H, class... T> void OUTLS(const H& h, const T&... t) {OUT(h,' '); OUTLS(t...); }

const int MX = 120;

static int mem[MX][MX];

int n;

int getD(int u, int v) {
    if(mem[u][v] != -1)
        return mem[u][v];
    return mem[u][v] = mem[v][u] = getDistance(u,v);
}

int hubDistance(int N, int sub) {
    n = N;
    RE(i,n) RE(j,n) mem[i][j] = -1;
    RE(i,n) mem[i][i] = 0;

    int u = 0, v=0;
    RE(i,n)
        if(getD(u,i) > getD(u,v))
            v = i;
    RE(i,n)
        if(getD(v,i) > getD(u,v))
            u = i;
    
    int res = getD(u,v);
    RE(i,n) {
        int nres = getD(0,i) + getD(v,i) - getD(0,v);
        nres /= 2;
        nres = getD(v,i) - nres;
        nres = max(nres, getD(u,v)-nres);
        res = min(res, nres);
    }

    int cnt1=0, cnt2=0;
    RE(i,n) {
        int nres = getD(0,i) + getD(v,i) - getD(0,v);
        nres /= 2;
        nres = getD(v,i) - nres;
        if(res != max(nres, getD(u,v)-nres)) {
            (nres < res ? cnt1 : cnt2)++;
        }
    }

    auto sameColor = [&](int x, int y) {
        int res = getD(0,x) + getD(v,y) - getD(x,y) - getD(0,v);
        return res > 0;
    };

    if(cnt1 > n/2 || cnt2 > n/2)
        return -res;

    vi seq = {0};
    vi buck;
    REP(i,1,n) {
        if(sameColor(seq.back(), i)) {
            buck.pb(i);
        } else {
            seq.pb(i);
            if(!buck.empty())
                seq.pb((buck.back())), buck.pop_back();
        }
    }

    int comp = seq.back();
    while(!seq.empty()) {
        if(sameColor(seq.back(), comp)) {
            if(seq.size() > 1)
                seq.pop_back(), seq.pop_back();
            else
                buck.pb(seq.back()), seq.pop_back();
        } else {
            if(buck.empty())
                return res;
            buck.pop_back();
            seq.pop_back();
        }
    }


    if(buck.empty())
        return res;
    return -res;
}

Compilation message (stderr)

towns.cpp: In lambda function:
towns.cpp:88:13: warning: declaration of 'res' shadows a previous local [-Wshadow]
   88 |         int res = getD(0,x) + getD(v,y) - getD(x,y) - getD(0,v);
      |             ^~~
towns.cpp:68:9: note: shadowed declaration is here
   68 |     int res = getD(u,v);
      |         ^~~
towns.cpp: In function 'int hubDistance(int, int)':
towns.cpp:55:28: warning: unused parameter 'sub' [-Wunused-parameter]
   55 | int hubDistance(int N, int sub) {
      |                        ~~~~^~~

• Subtask 1: 13 / 13
• Subtask 2: 12 / 12
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 13 / 13
• Subtask 6: 39 / 39