oj.uz

Submission #231739

# Submission time Handle Problem Language Result Execution time Memory
231739 2020-05-14T14:57:21 Z kshitij_sodani Boat (APIO16_boat) C++17
9 / 100
 326 ms 23368 KB 
#include <bits/stdc++.h>
#include <iostream>
using namespace std;
typedef int64_t llo;
#define mp make_pair
#define a first
#define b second
#define pb push_back
llo n,aa,bb;
map<llo,llo> dd;
llo si[2001];
llo mod=1000000007;
vector<llo> cc;
vector<pair<llo,llo>> it;
llo fac[501];
llo fac2[501];
llo pre[2001][501];
llo pre2[2001][501];
llo com[501][501];
llo dp[501][2001];
llo ind2=0;

llo mod2(llo ee,llo ff){
	if(ff==0){
		return 1;
	}
	llo ans=mod2(ee,ff/2);
	ans*=ans;
	ans%=mod;
	if(ff%2==1){
		ans*=ee;
		ans%=mod;
	}
	return ans;
}
void comp(){
	fac[0]=1;
	for(llo i=1;i<501;i++){
		fac[i]=fac[i-1]*i;
		fac[i]%=mod;
	}
	for(llo i=0;i<501;i++){
		fac2[i]=mod2(fac[i],mod-2);
	}
}
void ncr(){
	for(llo i=0;i<n+1;i++){
		for(llo j=0;j<=i;j++){
			com[i][j]=fac2[j]*fac2[i-j];
			com[i][j]%=mod;
			com[i][j]*=fac[i];
			com[i][j]%=mod;
		}
	}
}
void comp2(){
	fac[0]=1;
	for(llo i=0;i<ind2;i++){
		llo cur=1;
		pre[i][0]=0;
		for(llo j=1;j<n+1;j++){
			if(j<=si[i]){
				cur*=mod2(j,mod-2);
				cur%=mod;
				cur*=(si[i]-j+1);
				cur%=mod;
				pre[i][j]=cur;
			}
			else{
				pre[i][j]=0;
			}
		}		
	}
	for(llo i=0;i<ind2;i++){
		for(llo j=1;j<n+1;j++){
			pre2[i][j]=0;
			for(llo k=1;k<=j;k++){
				pre2[i][j]+=pre[i][k]*com[j-1][k-1];
				
			}
			pre2[i][j]%=mod;
		}
	}
}

int main(){
	cin>>n;
	for(llo i=0;i<n;i++){
		cin>>aa>>bb;
		cc.pb(aa);
		cc.pb(bb);
		it.pb({aa,bb});
	}
	comp();//factorial
	ncr();//computing iCj for i and j from 1 to n
	sort(cc.begin(),cc.end());
	for(llo i=0;i<cc.size();i++){
		if(i<cc.size()-1 and cc[i]==cc[i+1]){
			continue;
		}
		dd[cc[i]]=ind2;
		ind2+=1;

		si[dd[cc[i]]]=1;
		if(i<cc.size()-1){
			if(cc[i]<cc[i+1]-1){
				si[ind2]=cc[i+1]-cc[i]-1;
				ind2+=1;
			}
		}
	}
	comp2();
	for(llo i=0;i<n;i++){
		it[i].a=dd[it[i].a];
		it[i].b=dd[it[i].b];
	}

	for(llo i=0;i<n;i++){
		for(llo j=0;j<ind2;j++){
			dp[i][j]=0;
		}
	}
	for(llo j=0;j<ind2;j++){
		if(j>=it[0].a and j<=it[0].b){
			dp[0][j]=si[j];
		}
		if(j>0){
			dp[0][j]+=dp[0][j-1];
		}
		dp[0][j]%=mod;
	}
	for(llo i=1;i<n;i++){
		for(llo j=it[i].a;j<=it[i].b;j++){
			llo cot=1;
			for(llo k=i-1;k>=0;k--){
				if(j>0){
					dp[i][j]+=(dp[k][j-1])*pre2[j][cot];
					
				}
				if(it[k].a<=j and j<=it[k].b){
					cot+=1;
				}
			}
			dp[i][j]%=mod;
			dp[i][j]+=pre2[j][cot];
			dp[i][j]%=mod;
		}

		for(llo j=1;j<ind2;j++){
			dp[i][j]+=dp[i][j-1];
			dp[i][j]%=mod;
		}
		
	}
	llo ans=0;
	for(llo i=0;i<n;i++){
			ans+=dp[i][ind2-1];
			ans%=mod;
	}
	cout<<ans<<endl;







	
	
	return 0;
}

Compilation message

boat.cpp: In function 'int main()':
boat.cpp:97:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(llo i=0;i<cc.size();i++){
              ~^~~~~~~~~~
boat.cpp:98:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i<cc.size()-1 and cc[i]==cc[i+1]){
      ~^~~~~~~~~~~~
boat.cpp:105:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i<cc.size()-1){
      ~^~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 215 ms 16176 KB Output is correct
2 Correct 215 ms 16120 KB Output is correct
3 Correct 217 ms 16204 KB Output is correct
4 Correct 219 ms 16248 KB Output is correct
5 Correct 216 ms 16248 KB Output is correct
6 Correct 217 ms 16292 KB Output is correct
7 Correct 217 ms 16100 KB Output is correct
8 Correct 216 ms 16120 KB Output is correct
9 Correct 223 ms 16140 KB Output is correct
10 Correct 214 ms 16248 KB Output is correct
11 Correct 214 ms 16120 KB Output is correct
12 Correct 220 ms 16380 KB Output is correct
13 Correct 215 ms 16124 KB Output is correct
14 Correct 216 ms 16120 KB Output is correct
15 Correct 219 ms 16120 KB Output is correct
16 Correct 46 ms 6392 KB Output is correct
17 Correct 49 ms 6648 KB Output is correct
18 Correct 47 ms 6520 KB Output is correct
19 Correct 51 ms 6648 KB Output is correct
20 Correct 48 ms 6520 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 215 ms 16176 KB Output is correct
2 Correct 215 ms 16120 KB Output is correct
3 Correct 217 ms 16204 KB Output is correct
4 Correct 219 ms 16248 KB Output is correct
5 Correct 216 ms 16248 KB Output is correct
6 Correct 217 ms 16292 KB Output is correct
7 Correct 217 ms 16100 KB Output is correct
8 Correct 216 ms 16120 KB Output is correct
9 Correct 223 ms 16140 KB Output is correct
10 Correct 214 ms 16248 KB Output is correct
11 Correct 214 ms 16120 KB Output is correct
12 Correct 220 ms 16380 KB Output is correct
13 Correct 215 ms 16124 KB Output is correct
14 Correct 216 ms 16120 KB Output is correct
15 Correct 219 ms 16120 KB Output is correct
16 Correct 46 ms 6392 KB Output is correct
17 Correct 49 ms 6648 KB Output is correct
18 Correct 47 ms 6520 KB Output is correct
19 Correct 51 ms 6648 KB Output is correct
20 Correct 48 ms 6520 KB Output is correct
21 Incorrect 326 ms 23368 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 19 ms 4608 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 215 ms 16176 KB Output is correct
2 Correct 215 ms 16120 KB Output is correct
3 Correct 217 ms 16204 KB Output is correct
4 Correct 219 ms 16248 KB Output is correct
5 Correct 216 ms 16248 KB Output is correct
6 Correct 217 ms 16292 KB Output is correct
7 Correct 217 ms 16100 KB Output is correct
8 Correct 216 ms 16120 KB Output is correct
9 Correct 223 ms 16140 KB Output is correct
10 Correct 214 ms 16248 KB Output is correct
11 Correct 214 ms 16120 KB Output is correct
12 Correct 220 ms 16380 KB Output is correct
13 Correct 215 ms 16124 KB Output is correct
14 Correct 216 ms 16120 KB Output is correct
15 Correct 219 ms 16120 KB Output is correct
16 Correct 46 ms 6392 KB Output is correct
17 Correct 49 ms 6648 KB Output is correct
18 Correct 47 ms 6520 KB Output is correct
19 Correct 51 ms 6648 KB Output is correct
20 Correct 48 ms 6520 KB Output is correct
21 Incorrect 326 ms 23368 KB Output isn't correct
22 Halted 0 ms 0 KB -