oj.uz

Submission #678770

# Submission time Handle Problem Language Result Execution time Memory
678770 2023-01-06T14:01:09 Z jamezzz Event Hopping (BOI22_events) C++17
25 / 100
 1500 ms 15056 KB 
#include <bits/stdc++.h>
using namespace std;

#pragma GCC optimize("-O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")

#ifdef DEBUG
#define dbg(...) printf(__VA_ARGS__);
#define getchar_unlocked getchar
#else
#define dbg(...)
#endif
#define sf scanf
#define pf printf
#define fi first
#define se second
#define pb push_back
#define psf push_front
#define ppb pop_back
#define ppf pop_front
#define sz(x) (int)x.size()
#define mnto(x,y) x=min(x,(__typeof__(x))y)
#define mxto(x,y) x=max(x,(__typeof__(x))y)
#define INF 1023456789
#define LINF 1023456789123456789
#define all(x) x.begin(),x.end()
#define lb(x,v) (lower_bound(all(x),v)-x.begin())
#define ub(x,v) (upper_bound(all(x),v)-x.begin())
#define disc(x) sort(all(x));x.resize(unique(all(x))-x.begin());
typedef long long ll;
typedef long double ld;
typedef pair<int,int> ii;
typedef pair<ll,ll> pll;
typedef tuple<int,int,int> iii;
typedef tuple<int,int,int,int> iiii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
mt19937 rng(time(0));

#define mod 1000000007

inline int add(int a,int b){
	int r=a+b;
	while(r>=mod)r-=mod;
	while(r<0)r+=mod;
	return r;
}

inline int mult(int a,int b){
	return (int)(((ll)(a*b))%mod);
}

inline int rd(){
	int x=0;
	char ch=getchar_unlocked();
	while(!(ch&16))ch=getchar();//keep reading while current character is whitespace
    while(ch&16){//this will break when ‘\n’ or ‘ ‘ is encountered
		x=(x<<3)+(x<<1)+(ch&15);
		ch=getchar_unlocked();
	}
	return x;
}

#define maxn 100005

int n,q,m,s[maxn],e[maxn],st[20][2*maxn];
vector<int> d;

inline int qmn(int l,int r){
	int k=31-__builtin_clz(r-l+1);
	return min(st[k][l],st[k][r-(1<<k)+1]);
}

int main(){
	sf("%d%d",&n,&q);
	for(int i=0;i<n;++i){
		sf("%d%d",&s[i],&e[i]);
		d.pb(s[i]);d.pb(e[i]);
	}
	disc(d);
	for(int i=0;i<n;++i){
		s[i]=lb(d,s[i]);
		e[i]=lb(d,e[i]);
	}
	m=sz(d);
	for(int i=0;i<m;++i)st[0][i]=INF;
	for(int i=0;i<n;++i)mnto(st[0][e[i]],s[i]);
	for(int k=1;k<20;++k){
		for(int i=0;i+(1<<k)<=m;++i){
			st[k][i]=min(st[k-1][i],st[k-1][i+(1<<k-1)]);
		}
	}
	
	for(int i=0;i<q;++i){
		int x,y;sf("%d%d",&x,&y);
		if(x==y){
			pf("0\n");
			continue;
		}
		--x,--y;
		if(e[y]<e[x]){
			pf("impossible\n");
			continue;
		}
		int l=s[y],r=e[y];
		int ans=0;
		while(e[x]<l){
			int mn=qmn(l,r);
			if(l<=mn){
				ans=-1;
				break;
			}
			++ans;
			r=l-1;l=mn;
		}
		if(ans==-1)pf("impossible\n");
		else pf("%d\n",ans+1);
	}
}

Compilation message

events.cpp: In function 'int main()':
events.cpp:92:43: warning: suggest parentheses around '-' inside '<<' [-Wparentheses]
   92 |    st[k][i]=min(st[k-1][i],st[k-1][i+(1<<k-1)]);
      |                                          ~^~
events.cpp:77:4: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   77 |  sf("%d%d",&n,&q);
      |    ^
events.cpp:79:5: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |   sf("%d%d",&s[i],&e[i]);
      |     ^
events.cpp:97:13: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   97 |   int x,y;sf("%d%d",&x,&y);
      |             ^

Subtask #1
0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Execution timed out 1583 ms 8232 KB Time limit exceeded
3 Halted 0 ms 0 KB -

Subtask #2
10.0 / 10.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 2 ms 340 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 340 KB Output is correct

Subtask #3
0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 2 ms 340 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 212 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 1119 ms 1288 KB Output is correct
20 Execution timed out 1590 ms 988 KB Time limit exceeded
21 Halted 0 ms 0 KB -

Subtask #4
15.0 / 15.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 2 ms 340 KB Output is correct
4 Correct 2 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 468 KB Output is correct
8 Correct 1 ms 468 KB Output is correct
9 Correct 1 ms 340 KB Output is correct
10 Correct 0 ms 212 KB Output is correct
11 Correct 0 ms 340 KB Output is correct
12 Correct 1 ms 340 KB Output is correct
13 Correct 1 ms 340 KB Output is correct
14 Correct 1 ms 340 KB Output is correct
15 Correct 1 ms 340 KB Output is correct
16 Correct 1 ms 468 KB Output is correct
17 Correct 1 ms 468 KB Output is correct
18 Correct 1 ms 340 KB Output is correct
19 Correct 131 ms 8152 KB Output is correct
20 Correct 66 ms 8140 KB Output is correct
21 Correct 59 ms 8092 KB Output is correct
22 Correct 63 ms 10572 KB Output is correct
23 Correct 64 ms 15056 KB Output is correct
24 Correct 65 ms 15052 KB Output is correct
25 Correct 20 ms 1984 KB Output is correct

Subtask #5
0 / 20.0

# Verdict Execution time Memory Grader output
1 Execution timed out 1585 ms 8392 KB Time limit exceeded
2 Halted 0 ms 0 KB -

Subtask #6
0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 340 KB Output is correct
2 Execution timed out 1583 ms 8232 KB Time limit exceeded
3 Halted 0 ms 0 KB -