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Submission #31096

# Submission time Handle Problem Language Result Execution time Memory
31096 2017-08-09T18:08:42 Z tatatan Boat (APIO16_boat) C++11
100 / 100
 1296 ms 5176 KB 
#include <bits/stdc++.h>
#define mp make_pair
#define pb push_back
#define pii pair<int,int>
#define LL long long
#define st first
#define nd second
#define endl '\n'
using namespace std;

const int MAXN=505,mod=1e9+7;
int inverse[MAXN],dp[MAXN][MAXN*3],n,a[MAXN],b[MAXN];
vector<int> v;

void add(int &x,int y) {

	x+=y;
	if(x>=mod)
		x-=mod;

}

int bpow(int x,int y) {

	LL ret=1,t=x;
	while(y) {
		if(y&1)
			ret=(ret*t)%mod;
		y>>=1;
		t=(t*t)%mod;
	}
	return (int)ret;

}

int main() {

	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cin>>n;
	for(int i=1;i<=n;++i) {
		cin>>a[i]>>b[i];
		v.pb(a[i]);
		v.pb(b[i]+1);
		inverse[i]=bpow(i,mod-2);
	}
	v.pb(0);
	sort(v.begin(),v.end());
	v.resize(unique(v.begin(),v.end())-v.begin());
	for(int i=1;i<=n;++i) {
		a[i]=lower_bound(v.begin(),v.end(),a[i])-v.begin();
		b[i]=lower_bound(v.begin(),v.end(),b[i]+1)-v.begin();	
	}
	for(int i=0;i<v.size();++i)
		dp[n+1][i]=1;
	for(int i=n;i>=1;--i) {
		for(int j=v.size()-2;j>=1;--j) {
			add(dp[i][j],dp[i][j+1]);
			if(!(j>=a[i]&&j<b[i]))
				continue;
			LL nCr=1,x=v[j+1]-v[j],y=1;
			for(int k=i;k<=n;++k) {
				if(j>=a[k]&&j<b[k]) {
					nCr=(nCr*x)%mod;
					nCr=(nCr*inverse[y])%mod;
					++x; ++y;
				}
				add(dp[i][j],(nCr*dp[k+1][j+1])%mod);
			}
			//cout<<i<<" "<<j<<" "<<v[j]<<" "<<dp[i][j]<<endl;
		}
	}
	int ans=0;
	for(int i=1;i<=n;++i)
		add(ans,dp[i][1]);
	cout<<ans<< endl;

}

Compilation message

boat.cpp: In function 'int main()':
boat.cpp:54:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0;i<v.size();++i)
               ^

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5176 KB Output is correct
2 Correct 0 ms 5176 KB Output is correct
3 Correct 6 ms 5176 KB Output is correct
4 Correct 6 ms 5176 KB Output is correct
5 Correct 6 ms 5176 KB Output is correct
6 Correct 3 ms 5176 KB Output is correct
7 Correct 3 ms 5176 KB Output is correct
8 Correct 3 ms 5176 KB Output is correct
9 Correct 3 ms 5176 KB Output is correct
10 Correct 3 ms 5176 KB Output is correct
11 Correct 3 ms 5176 KB Output is correct
12 Correct 3 ms 5176 KB Output is correct
13 Correct 6 ms 5176 KB Output is correct
14 Correct 6 ms 5176 KB Output is correct
15 Correct 6 ms 5176 KB Output is correct
16 Correct 0 ms 5176 KB Output is correct
17 Correct 0 ms 5176 KB Output is correct
18 Correct 3 ms 5176 KB Output is correct
19 Correct 0 ms 5176 KB Output is correct
20 Correct 3 ms 5176 KB Output is correct

Subtask #2
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5176 KB Output is correct
2 Correct 0 ms 5176 KB Output is correct
3 Correct 6 ms 5176 KB Output is correct
4 Correct 6 ms 5176 KB Output is correct
5 Correct 6 ms 5176 KB Output is correct
6 Correct 3 ms 5176 KB Output is correct
7 Correct 3 ms 5176 KB Output is correct
8 Correct 3 ms 5176 KB Output is correct
9 Correct 3 ms 5176 KB Output is correct
10 Correct 3 ms 5176 KB Output is correct
11 Correct 3 ms 5176 KB Output is correct
12 Correct 3 ms 5176 KB Output is correct
13 Correct 6 ms 5176 KB Output is correct
14 Correct 6 ms 5176 KB Output is correct
15 Correct 6 ms 5176 KB Output is correct
16 Correct 0 ms 5176 KB Output is correct
17 Correct 0 ms 5176 KB Output is correct
18 Correct 3 ms 5176 KB Output is correct
19 Correct 0 ms 5176 KB Output is correct
20 Correct 3 ms 5176 KB Output is correct
21 Correct 863 ms 5176 KB Output is correct
22 Correct 806 ms 5176 KB Output is correct
23 Correct 736 ms 5176 KB Output is correct
24 Correct 773 ms 5176 KB Output is correct
25 Correct 819 ms 5176 KB Output is correct
26 Correct 1146 ms 5176 KB Output is correct
27 Correct 1063 ms 5176 KB Output is correct
28 Correct 1033 ms 5176 KB Output is correct
29 Correct 1136 ms 5176 KB Output is correct
30 Correct 9 ms 5176 KB Output is correct
31 Correct 6 ms 5176 KB Output is correct
32 Correct 9 ms 5176 KB Output is correct
33 Correct 9 ms 5176 KB Output is correct
34 Correct 9 ms 5176 KB Output is correct
35 Correct 6 ms 5176 KB Output is correct
36 Correct 9 ms 5176 KB Output is correct
37 Correct 9 ms 5176 KB Output is correct
38 Correct 9 ms 5176 KB Output is correct

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5176 KB Output is correct
2 Correct 3 ms 5176 KB Output is correct
3 Correct 6 ms 5176 KB Output is correct
4 Correct 6 ms 5176 KB Output is correct
5 Correct 6 ms 5176 KB Output is correct
6 Correct 9 ms 5176 KB Output is correct
7 Correct 9 ms 5176 KB Output is correct
8 Correct 9 ms 5176 KB Output is correct
9 Correct 9 ms 5176 KB Output is correct
10 Correct 6 ms 5176 KB Output is correct
11 Correct 6 ms 5176 KB Output is correct
12 Correct 6 ms 5176 KB Output is correct
13 Correct 6 ms 5176 KB Output is correct
14 Correct 6 ms 5176 KB Output is correct
15 Correct 6 ms 5176 KB Output is correct
16 Correct 3 ms 5176 KB Output is correct
17 Correct 3 ms 5176 KB Output is correct
18 Correct 3 ms 5176 KB Output is correct
19 Correct 3 ms 5176 KB Output is correct
20 Correct 3 ms 5176 KB Output is correct

Subtask #4
42.0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 3 ms 5176 KB Output is correct
2 Correct 0 ms 5176 KB Output is correct
3 Correct 6 ms 5176 KB Output is correct
4 Correct 6 ms 5176 KB Output is correct
5 Correct 6 ms 5176 KB Output is correct
6 Correct 3 ms 5176 KB Output is correct
7 Correct 3 ms 5176 KB Output is correct
8 Correct 3 ms 5176 KB Output is correct
9 Correct 3 ms 5176 KB Output is correct
10 Correct 3 ms 5176 KB Output is correct
11 Correct 3 ms 5176 KB Output is correct
12 Correct 3 ms 5176 KB Output is correct
13 Correct 6 ms 5176 KB Output is correct
14 Correct 6 ms 5176 KB Output is correct
15 Correct 6 ms 5176 KB Output is correct
16 Correct 0 ms 5176 KB Output is correct
17 Correct 0 ms 5176 KB Output is correct
18 Correct 3 ms 5176 KB Output is correct
19 Correct 0 ms 5176 KB Output is correct
20 Correct 3 ms 5176 KB Output is correct
21 Correct 863 ms 5176 KB Output is correct
22 Correct 806 ms 5176 KB Output is correct
23 Correct 736 ms 5176 KB Output is correct
24 Correct 773 ms 5176 KB Output is correct
25 Correct 819 ms 5176 KB Output is correct
26 Correct 1146 ms 5176 KB Output is correct
27 Correct 1063 ms 5176 KB Output is correct
28 Correct 1033 ms 5176 KB Output is correct
29 Correct 1136 ms 5176 KB Output is correct
30 Correct 9 ms 5176 KB Output is correct
31 Correct 6 ms 5176 KB Output is correct
32 Correct 9 ms 5176 KB Output is correct
33 Correct 9 ms 5176 KB Output is correct
34 Correct 9 ms 5176 KB Output is correct
35 Correct 6 ms 5176 KB Output is correct
36 Correct 9 ms 5176 KB Output is correct
37 Correct 9 ms 5176 KB Output is correct
38 Correct 9 ms 5176 KB Output is correct
39 Correct 3 ms 5176 KB Output is correct
40 Correct 3 ms 5176 KB Output is correct
41 Correct 6 ms 5176 KB Output is correct
42 Correct 6 ms 5176 KB Output is correct
43 Correct 6 ms 5176 KB Output is correct
44 Correct 9 ms 5176 KB Output is correct
45 Correct 9 ms 5176 KB Output is correct
46 Correct 9 ms 5176 KB Output is correct
47 Correct 9 ms 5176 KB Output is correct
48 Correct 6 ms 5176 KB Output is correct
49 Correct 6 ms 5176 KB Output is correct
50 Correct 6 ms 5176 KB Output is correct
51 Correct 6 ms 5176 KB Output is correct
52 Correct 6 ms 5176 KB Output is correct
53 Correct 6 ms 5176 KB Output is correct
54 Correct 3 ms 5176 KB Output is correct
55 Correct 3 ms 5176 KB Output is correct
56 Correct 3 ms 5176 KB Output is correct
57 Correct 3 ms 5176 KB Output is correct
58 Correct 3 ms 5176 KB Output is correct
59 Correct 969 ms 5176 KB Output is correct
60 Correct 843 ms 5176 KB Output is correct
61 Correct 773 ms 5176 KB Output is correct
62 Correct 823 ms 5176 KB Output is correct
63 Correct 933 ms 5176 KB Output is correct
64 Correct 1296 ms 5176 KB Output is correct
65 Correct 1233 ms 5176 KB Output is correct
66 Correct 1146 ms 5176 KB Output is correct
67 Correct 1226 ms 5176 KB Output is correct
68 Correct 1149 ms 5176 KB Output is correct
69 Correct 753 ms 5176 KB Output is correct
70 Correct 709 ms 5176 KB Output is correct
71 Correct 703 ms 5176 KB Output is correct
72 Correct 889 ms 5176 KB Output is correct
73 Correct 836 ms 5176 KB Output is correct
74 Correct 146 ms 5176 KB Output is correct
75 Correct 156 ms 5176 KB Output is correct
76 Correct 163 ms 5176 KB Output is correct
77 Correct 166 ms 5176 KB Output is correct
78 Correct 169 ms 5176 KB Output is correct