Submission #390374

#	Time	Username	Problem	Language	Result	Execution time	Memory
390374		arwaeystoamneg	Traffic (IOI10_traffic)	C++17	100 / 100	1280 ms	162872 KiB

traffic

// EXPLOSION!
#define _CRT_SECURE_NO_WARNINGS
#include<bits/stdc++.h>
#include<unordered_set>
#include<unordered_map>
#include<chrono>

using namespace std;
typedef pair<int, int> pii;
typedef long long ll;
typedef pair<ll, ll> pll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<pair<int, int>> vpi;
typedef vector<pair<ll, ll>> vpll;

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

#define pb push_back
#define mp make_pair
#define rsz resize
#define sz(x) int(x.size())
#define all(x) x.begin(),x.end()
#define f first
#define s second
#define cont continue
//#define endl '\n'
//#define ednl '\n'
#define test int testc;cin>>testc;while(testc--)
#define pr(a, b) trav(x,a)cerr << x << b; cerr << endl;
#define message cout << "Hello World" << endl;
const int dx[4] = { 1,0,-1,0 }, dy[4] = { 0,1,0,-1 }; // for every grid problem!!
const ll linf = 4000000000000000000LL;
const ll inf = 1000000007;//998244353    

void pv(vi a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vll a) { trav(x, a)cout << x << " "; cout << endl; }void pv(vector<vi>a) {
	F0R(i, sz(a)) { cout << i << endl; pv(a[i]); cout << endl; }
}void pv(vector<vll>a) { F0R(i, sz(a)) { cout << i << endl; pv(a[i]); }cout << endl; }void pv(vector<string>a) { trav(x, a)cout << x << endl; cout << endl; }
void setIO(string s) {
	ios_base::sync_with_stdio(0); cin.tie(0);
	if (sz(s))
	{
		freopen((s + ".in").c_str(), "r", stdin);
		if (s != "test1")
			freopen((s + ".out").c_str(), "w", stdout);
	}
}
#include "traffic.h"
int n;
const int MAX = 1e6 + 5;
int a[MAX], parent[MAX];
ll sizes[MAX], total;
vi adj[MAX];

void dfs(int i, int p = -1)
{
	parent[i] = p;
	sizes[i] = a[i];
	trav(x, adj[i])
	{
		if (x == p)continue;
		dfs(x, i);
		sizes[i] += sizes[x];
	}
}
int LocateCentre(int N, int pp[], int S[], int D[]) 
{
	n = N;
	F0R(i, n)a[i] = pp[i], total += a[i];
	F0R(i, n - 1)
	{
		adj[S[i]].pb(D[i]);
		adj[D[i]].pb(S[i]);
	}
	dfs(0);
	pll ans = { linf,-1 };
	F0R(i, n)
	{
		ll val = total - sizes[i];
		trav(x, adj[i])
		{
			if (x == parent[i])continue;
			val = max(val, sizes[x]);
		}
		ans = min(ans, { val,i });
	}
	return ans.s;
}
#ifdef arwaeystoamneg
static int N, P[1000000], S[1000000], D[1000000];

int main()
{
	setIO("test1");

	int i;
	scanf("%d", &N);
	for (i = 0; i < N; i++) scanf("%d", &P[i]);
	for (i = 0; i < N - 1; i++) scanf("%d%d", &S[i], &D[i]);
	int r = LocateCentre(N, P, S, D);
	printf("%d\n", r);
	return 0;

}
#endif

Compilation message (stderr)

traffic.cpp: In function 'void setIO(std::string)':
traffic.cpp:48:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   48 |   freopen((s + ".in").c_str(), "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
traffic.cpp:50:11: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   50 |    freopen((s + ".out").c_str(), "w", stdout);
      |    ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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