Submission #644849

#	Time	Username	Problem	Language	Result	Execution time	Memory
644849		ghostwriter	Traffic (IOI10_traffic)	C++14	100 / 100	4275 ms	202184 KiB

traffic

#include "traffic.h"
#include <bits/stdc++.h>
using namespace std;
#ifdef LOCAL
#include <debug.h>
#include "grader.cpp"
#endif
#define ft front
#define bk back
#define st first
#define nd second
#define ins insert
#define ers erase
#define pb push_back
#define pf push_front
#define _pb pop_back
#define _pf pop_front
#define lb lower_bound
#define ub upper_bound
#define mtp make_tuple
#define bg begin
#define ed end
#define all(x) (x).bg(), (x).ed()
#define sz(x) (int)(x).size()
typedef long long ll; typedef unsigned long long ull;
typedef double db; typedef long double ldb;
typedef pair<int, int> pi; typedef pair<ll, ll> pll;
typedef vector<int> vi; typedef vector<ll> vll; typedef vector<pi> vpi; typedef vector<pll> vpll;
typedef string str;
template<typename T> T gcd(T a, T b) { return (b == 0? a : gcd(b, a % b)); }
template<typename T> T lcm(T a, T b) { return a / gcd(a, b) * b; }
#define FOR(i, l, r) for (int (i) = (l); (i) <= (r); ++(i))
#define FOS(i, r, l) for (int (i) = (r); (i) >= (l); --(i))
#define FRN(i, n) for (int (i) = 0; (i) < (n); ++(i))
#define FSN(i, n) for (int (i) = (n) - 1; (i) >= 0; --(i))
#define EACH(i, x) for (auto &(i) : (x))
#define WHILE while
#define file "TEST"
mt19937 rd(chrono::steady_clock::now().time_since_epoch().count());
ll rand(ll l, ll r) { return uniform_int_distribution<ll>(l, r)(rd); }
/*
----------------------------------------------------------------
    END OF TEMPLATE
----------------------------------------------------------------
    Tran The Bao - ghostwriter
    Training for VOI23 gold medal
----------------------------------------------------------------
    DIT ME CHUYEN BAO LOC
----------------------------------------------------------------
*/
const int oo = 2e9 + 5;
const int MAXN = 1e6;
int s[MAXN], ans[MAXN];
vi adj[MAXN];
multiset<int> s1;
void dfs(int u, int p) {
    EACH(v, adj[u]) {
        if (v == p) continue;
        dfs(v, u);
        s[u] += s[v];
    }
    if (p != -1) s1.insert(s[u]);
}
void dfs1(int u, int p) {
    ans[u] = *--s1.ed();
    EACH(v, adj[u]) {
        if (v == p) continue;
        s1.erase(s1.lb(s[v]));
        s[v] = s[0] - s[v];
        s1.insert(s[v]);
        dfs1(v, u);
        s1.erase(s1.lb(s[v]));
        s[v] = s[0] - s[v];
        s1.insert(s[v]);
    }
}
int LocateCentre(int N, int pp[], int S[], int D[]) {
    if (N == 1) return 0;
    FRN(i, N) s[i] = pp[i];
    FRN(i, N - 1) {
        int u = S[i], v = D[i];
        adj[u].pb(v);
        adj[v].pb(u);
    }
    dfs(0, -1);
    dfs1(0, -1);
    int rs = oo, pos = -1;
    FRN(i, N)
        if (rs > ans[i]) {
            rs = ans[i];
            pos = i;
        }
    return pos;
}
/*
10
1 1 1 1 1 1 1 1 1 1
0 1
1 2
2 3
3 4
4 5
5 6
6 7
7 8
8 9
----------------------------------------------------------------
From Benq:
    stuff you should look for
        * int overflow, array bounds
        * special cases (n=1?)
        * do smth instead of nothing and stay organized
        * WRITE STUFF DOWN
        * DON'T GET STUCK ON ONE APPROACH
----------------------------------------------------------------
*/

Compilation message (stderr)

traffic.cpp: In function 'void dfs(int, int)':
traffic.cpp:36:31: warning: unnecessary parentheses in declaration of 'v' [-Wparentheses]
   36 | #define EACH(i, x) for (auto &(i) : (x))
      |                               ^
traffic.cpp:57:5: note: in expansion of macro 'EACH'
   57 |     EACH(v, adj[u]) {
      |     ^~~~
traffic.cpp: In function 'void dfs1(int, int)':
traffic.cpp:36:31: warning: unnecessary parentheses in declaration of 'v' [-Wparentheses]
   36 | #define EACH(i, x) for (auto &(i) : (x))
      |                               ^
traffic.cpp:66:5: note: in expansion of macro 'EACH'
   66 |     EACH(v, adj[u]) {
      |     ^~~~
traffic.cpp: In function 'int LocateCentre(int, int*, int*, int*)':
traffic.cpp:34:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   34 | #define FRN(i, n) for (int (i) = 0; (i) < (n); ++(i))
      |                            ^
traffic.cpp:79:5: note: in expansion of macro 'FRN'
   79 |     FRN(i, N) s[i] = pp[i];
      |     ^~~
traffic.cpp:34:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   34 | #define FRN(i, n) for (int (i) = 0; (i) < (n); ++(i))
      |                            ^
traffic.cpp:80:5: note: in expansion of macro 'FRN'
   80 |     FRN(i, N - 1) {
      |     ^~~
traffic.cpp:34:28: warning: unnecessary parentheses in declaration of 'i' [-Wparentheses]
   34 | #define FRN(i, n) for (int (i) = 0; (i) < (n); ++(i))
      |                            ^
traffic.cpp:88:5: note: in expansion of macro 'FRN'
   88 |     FRN(i, N)
      |     ^~~

• Subtask 1: 25 / 25
• Subtask 2: 25 / 25
• Subtask 3: 25 / 25
• Subtask 4: 25 / 25