Submission #1106246

# Submission time Handle Problem Language Result Execution time Memory
1106246 2024-10-29T16:22:48 Z _rain_ Boat (APIO16_boat) C++14
27 / 100
506 ms 4680 KB
#include<bits/stdc++.h>
using namespace std;
 
typedef long long ll ;
typedef pair<int,int> ii;
#define fi first
#define se second
#define name "main"
 
const int N=(int)500;
const int MOD=(int)1e9+7;
	int add(int a,int b){
		return a+b>=MOD?a+b-MOD:a+b;
	}
	int sub(int a,int b){
		return a-b<0?a-b+MOD:a-b;
	}
	int mul(int a,int b){
		return (ll)a*b%MOD;
	}
	int power(int a,int b){
		int res=1;
		for(;b;b>>=1,a=mul(a,a))
			if (b&1) res=mul(res,a);
		return res;
	}
vector<int>nen;
vector<ii>line;
int a[N+2],b[N+2],n;
int L[N+2]={},R[N+2]={},f[N+2][2*N+2]={},dp[N+2][2*N+2]={};
int sing[N+2]={},fact[N+2]={},inv[N+2]={},w[N+2]={};
int Combine(int x,int y){
	if (x>y) return 0;
	return (ll)fact[y]*inv[y-x]%MOD*inv[x]%MOD;
}

int C(int k,int n){
	if (k>n) return 0;
	int res=1;
	for(int i=n-k+1;i<=n;++i) res=mul(res,i);
	return mul(res,inv[k]);
}
bool intersec(ii x,int a,int b){
	if (b<x.fi||a>x.se) return false;
	return true;
}
 
void build(){
	memset(L,0x3f,sizeof L);
	memset(R,-0x3f,sizeof R);
	fact[0]=1;
	for(int i=1;i<=N;++i) fact[i]=mul(fact[i-1],i);
	inv[N]=power(fact[N],MOD-2);
	for(int i=N;i>=1;--i) inv[i-1]=mul(inv[i],i);
	for(int id=1;id<=line.size();++id){
		int dodai=line[id-1].se-line[id-1].fi+1;
		for(int j=1;j<=n;++j) w[j]=C(j,dodai);
		for(int j=1;j<=n;++j){
			for(int c=1;c<=j;++c)
				f[id][j]=add(f[id][j],mul(Combine(c-1,j-1),w[c]));
		}
	}
	for(int i=1;i<=n;++i){
		for(int j=1;j<=line.size();++j){
			if (intersec(line[j-1],a[i],b[i])) 
				L[i]=min(L[i],j),R[i]=max(R[i],j);
		}
	}
	return;
}
 
int32_t main(){
	ios::sync_with_stdio(0);
	cin.tie(0); cout.tie(0);

	cin>>n;
	for(int i=1;i<=n;++i){
		cin>>a[i]>>b[i];
		nen.push_back(a[i]);
		nen.push_back(b[i]);
		nen.push_back(a[i]-1);
	}
	sort(nen.begin(),nen.end());
	nen.resize(unique(nen.begin(),nen.end())-nen.begin());
	for(int i=1;i<nen.size();++i){
		if (i-1==0) line.push_back({nen[i-1],nen[i]});
		else line.push_back({nen[i-1]+1,nen[i]});
	}
	build();
	for(int i=0;i<=line.size();++i) dp[0][i]=1;
	for(int i=1;i<=n;++i){
		// cout<<i<<'\n';
		for(int id=L[i];id<=R[i];++id){
			int cnt=0;
			pair<int,int> xx=line[id-1];
			if (id==L[i]){
				int dodai=line[id-1].se-a[i]+1;
				for(int j=0;j<=n;++j) sing[j]=0;
				for(int j=1;j<=n;++j) w[j]=C(j,dodai);
				for(int j=1;j<=n;++j){
					for(int c=1;c<=j;++c)
						sing[j]=add(sing[j],mul(Combine(c-1,j),w[c]));
				}
				xx={a[i],line[id-1].se};
			}
			for(int j=i;j>=1;--j){
				if (intersec(xx,a[j],b[j])) ++cnt;
				if (id==L[i]) dp[i][id]=add(dp[i][id],mul(sing[cnt],dp[j-1][id-1]));
				else dp[i][id]=add(dp[i][id],mul(f[id][cnt],dp[j-1][id-1]));
			}
		}
		for(int j=1;j<=line.size();++j) dp[i][j]=add(dp[i][j],dp[i][j-1]);
	}
	int ans=0;
	for(int i=1;i<=n;++i) ans=add(ans,dp[i][line.size()]);
	cout<<ans;
	exit(0);
}

Compilation message

boat.cpp: In function 'void build()':
boat.cpp:55:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |  for(int id=1;id<=line.size();++id){
      |               ~~^~~~~~~~~~~~~
boat.cpp:64:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   64 |   for(int j=1;j<=line.size();++j){
      |               ~^~~~~~~~~~~~~
boat.cpp: In function 'int32_t main()':
boat.cpp:85:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   85 |  for(int i=1;i<nen.size();++i){
      |              ~^~~~~~~~~~~
boat.cpp:90:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   90 |  for(int i=0;i<=line.size();++i) dp[0][i]=1;
      |              ~^~~~~~~~~~~~~
boat.cpp:112:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  112 |   for(int j=1;j<=line.size();++j) dp[i][j]=add(dp[i][j],dp[i][j-1]);
      |               ~^~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Runtime error 506 ms 4680 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Runtime error 506 ms 4680 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -
# Verdict Execution time Memory Grader output
1 Correct 20 ms 1924 KB Output is correct
2 Correct 20 ms 1888 KB Output is correct
3 Correct 20 ms 1872 KB Output is correct
4 Correct 20 ms 1872 KB Output is correct
5 Correct 20 ms 1872 KB Output is correct
6 Correct 21 ms 1884 KB Output is correct
7 Correct 21 ms 1872 KB Output is correct
8 Correct 21 ms 1872 KB Output is correct
9 Correct 23 ms 2040 KB Output is correct
10 Correct 20 ms 2016 KB Output is correct
11 Correct 22 ms 1872 KB Output is correct
12 Correct 19 ms 1872 KB Output is correct
13 Correct 19 ms 1872 KB Output is correct
14 Correct 19 ms 1872 KB Output is correct
15 Correct 19 ms 2000 KB Output is correct
16 Correct 11 ms 1360 KB Output is correct
17 Correct 11 ms 1360 KB Output is correct
18 Correct 11 ms 1368 KB Output is correct
19 Correct 14 ms 1296 KB Output is correct
20 Correct 12 ms 1360 KB Output is correct
# Verdict Execution time Memory Grader output
1 Runtime error 506 ms 4680 KB Execution killed with signal 11
2 Halted 0 ms 0 KB -