Submission #889211

#	Time	Username	Problem	Language	Result	Execution time	Memory
889211		Cutebol	Railway Trip (JOI17_railway_trip)	C++17	20 / 100	2047 ms	17328 KiB

railway_trip

#include <bits/stdc++.h>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
//using namespace __gnu_pbds;

bool YES(bool f){ if(f) cout << "Yes\n" ; else cout << "No\n" ; return f ; }
void YES(){cout << "Yes\n" ;}
void NO(){cout << "No\n" ;}
void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
//#define ordered_set tree<int, null_type,less_equal<int>, rb_tree_tag,tree_order_statistics_node_update>
#define ios ios_base::sync_with_stdio(0) ; cin.tie(0) ; cout.tie(0);
#define int long long
#define ld long double
#define pii pair <int , int>
#define ff first
#define ss second
#define endl '\n'

const int N = 3e5 + 5 ;
const int inf = 1e18 ;
const int mod = 998244353 ;
const double eps = 1e-8 ;

int binpow( int a , int b ){
  if ( b == 0 ) return 1 ;
  int x = binpow ( a , b/2 ) ;
  if ( !(b%2) ) return (x*x) ;
  return (x*x*a) ;
}
template <class T>
bool chmax( T& x , const T& y ){
  bool f = 0 ;
  if ( x < y ) x = y , f = 1 ;
  return f ;
}
template <class T>
bool chmin( T &x , const T &y ){
  bool f = 0 ;
  if ( x > y ) x = y , f = 1 ;
  return f ;
}

//code

int n , k , q ;
int a[N] , d[N] ;
vector <int> g[N] ;

int bfs ( int s , int x ){
	for ( int i = 0 ; i <= n ; i ++ ) d[i] = inf ;
	d[s] = 0 ;
	queue <int> q ;
	q.push(s) ;
	while (!q.empty()){
		int v = q.front() ;
		//cout << v << endl ;
		q.pop() ;
		for ( auto to : g[v] ){
			if ( chmin (d[to] , d[v] + 1 )) q.push(to) ;
		}
	}
	return d[x]-1 ;
}

void solve(){
	
	cin >> n >> k >> q ;
	for ( int i = 1 ; i <= n ; i ++  ) cin >> a[i] ;
	for ( int i = 1 ; i < n ; i ++ ){
		int mn = 0 ;
		for ( int j = i+1 ; j <= n ; j ++ ){
			if ( chmax ( mn , a[j]) ){
				g[i].push_back(j) ;
				g[j].push_back(i) ;
			}
			if ( mn >= a[i] ) break ;
		}
	}
	while ( q -- ){
		int x , y ; cin >> x >> y ;
		cout << bfs(x,y) << endl ;
	}
	
	
}

signed main(){
    ios ;
	int t = 1 ;
	//cin >> t ;
	while ( t -- ) solve() ;
}

Compilation message (stderr)

railway_trip.cpp: In function 'void fopn(std::string)':
railway_trip.cpp:10:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
railway_trip.cpp:10:72: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 | void fopn(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                                 ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 0 / 25
• Subtask 4: 0 / 55