Submission #118746

#	Time	Username	Problem	Language	Result	Execution time	Memory
118746		Sorting	Highway Tolls (IOI18_highway)	C++14	Compilation error	0 ms	0 KiB

highway

#include <bits/stdc++.h>

using namespace std;

long long ask(vector<int> w);
void answer(int s, int t);

const int MAXN = 1e5 + 7;

mt19937 mt();

long long n, m;
vector<int> adj[MAXN], idx[MAXN], w;
vector<pair<int, int> > e;

void dfs(int u, int pr = -1, int d = 0){
	for(int i = 0; i < adj[u].size(); i++){
		int to = adj[u][i], j = idx[u][i];

		e.push_back({d + 1, j});
		dfs(to, u, d + 1);
	}
}

void find_pair(int N, vector<int> U, vector<int> V, int A, int B){
	n = N;
	m = U.size();

	for(int i = 0; i < m; i++){
		adj[V[i]].push_back(U[i]);
		adj[U[i]].push_back(V[i]);

		idx[V[i]].push_back(i);
		idx[U[i]].push_back(i);
		w.push_back(0);
	}

	long long a = A, b = B;
	long long sqrtn = sqrt(n), sm = ask(w);

	dfs(0);

	sort(e.begin(), e.end());

	int l = 0, r = m;

	while(l != r){
		int mid = (l + r) / 2;

		for(int i = 0; i < m; i++){
			w[i] = 0;
		}
		for(int i = mid + 1; i <= r; i++){
			w[e[i].second] = true;
		}

		long long score = ask(w);
		score -= sm;

		if(score){
			l = mid + 1;
		}
		else{
			r = mid;
		}
	}

	answer(0, l);
}

/*
9 1 2
4 8
4 2
8 0
2 5
2 7
2 3
0 1
0 6
*/

Compilation message (stderr)

highway.cpp: In function 'void dfs(int, int, int)':
highway.cpp:17:19: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i = 0; i < adj[u].size(); i++){
                 ~~^~~~~~~~~~~~~~~
highway.cpp: In function 'void find_pair(int, std::vector<int>, std::vector<int>, int, int)':
highway.cpp:38:12: warning: unused variable 'a' [-Wunused-variable]
  long long a = A, b = B;
            ^
highway.cpp:38:19: warning: unused variable 'b' [-Wunused-variable]
  long long a = A, b = B;
                   ^
highway.cpp:39:12: warning: unused variable 'sqrtn' [-Wunused-variable]
  long long sqrtn = sqrt(n), sm = ask(w);
            ^~~~~
/tmp/cczd7YFI.o: In function `find_pair(int, std::vector<int, std::allocator<int> >, std::vector<int, std::allocator<int> >, int, int)':
highway.cpp:(.text+0x5b3): undefined reference to `ask(std::vector<int, std::allocator<int> >)'
highway.cpp:(.text+0x778): undefined reference to `ask(std::vector<int, std::allocator<int> >)'
collect2: error: ld returned 1 exit status