답안 #403429

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
403429	2021-05-13T07:24:07 Z	myrcella	Boat (APIO16_boat)	C++17	100 / 100	1133 ms	8420 KB

boat

//by szh
#include<bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 0x3f
#define rep(i,a,b) for (int i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define ll long long
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
void inc(int &a,int b) {a=(a+b)%mod;}
void dec(int &a,int b) {a=(a-b+mod)%mod;}
int lowbit(int x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}

const int maxn=1e3+10;

int n;
int f[2][maxn][maxn];
int a[maxn],b[maxn];
map <int,int> mp;
int pm[maxn];
ll inv[maxn];
int sum[maxn];

int main() {
//	freopen("input.txt","r",stdin);	
	std::ios::sync_with_stdio(false);cin.tie();
	cin>>n;
	rep(i,1,maxn) inv[i]=p0w(i,mod-2);
	mp[0]=1;
	rep(i,1,n+1) cin>>a[i]>>b[i],a[i]--,mp[a[i]]=mp[b[i]]=1;
	int tot=0;
	for (auto &it:mp) it.se=tot,pm[tot++]=it.fi;
	int lst=0,cur=1;
	f[lst][0][0]=1;
	rep(i,1,n+1) {
		memset(sum,0,sizeof(sum));
		memset(f[cur],0,sizeof(f[cur]));
		rep(j,0,tot) 
			rep(k,0,i) {
				if (f[lst][j][k]==0) continue;
				//doesn't choose
				inc(f[cur][j][k],f[lst][j][k]); 
				inc(sum[j],f[lst][j][k]);
//				cout<<i-1<<" "<<j<<" "<<k<<" "<<f[lst][j][k]<<endl;
			}
//		debug(sum[0]),debug(sum[1]),debug(sum[2]);
		rep(j,mp[a[i]]+1,mp[b[i]]+1) {
			rep(k,0,i) {	
				//choose from the same segment
				if (pm[j]-pm[j-1]>=k+1) inc(f[cur][j][k+1],1ll*f[lst][j][k]*(pm[j]-pm[j-1]-k)%mod*inv[k+1]%mod);
			}
		}
		rep(j,1,tot) inc(sum[j],sum[j-1]);
//		debug(sum[1]),debug(sum[2]),debug(sum[3]);
//		debug(a[i]),debug(b[i]),debug(mp[a[i]]),debug(mp[b[i]]);
		rep(j,mp[a[i]],mp[b[i]]) {
			//start from a new segment
			inc(f[cur][j+1][1],1ll*sum[j]*(pm[j+1]-pm[j])%mod);
		}
		
		swap(lst,cur);
	}
	int ans=0;
	rep(i,1,tot)
		rep(j,1,n+1) inc(ans,f[lst][i][j]);
	cout<<ans<<endl;
	return 0;
}

Subtask #1

9.0 / 9.0

#	결과	실행 시간	메모리	Grader output
1	Correct	288 ms	8364 KB	Output is correct
2	Correct	290 ms	8352 KB	Output is correct
3	Correct	286 ms	8352 KB	Output is correct
4	Correct	291 ms	8372 KB	Output is correct
5	Correct	300 ms	8268 KB	Output is correct
6	Correct	283 ms	8364 KB	Output is correct
7	Correct	296 ms	8356 KB	Output is correct
8	Correct	314 ms	8268 KB	Output is correct
9	Correct	300 ms	8268 KB	Output is correct
10	Correct	298 ms	8348 KB	Output is correct
11	Correct	295 ms	8356 KB	Output is correct
12	Correct	298 ms	8268 KB	Output is correct
13	Correct	295 ms	8352 KB	Output is correct
14	Correct	298 ms	8360 KB	Output is correct
15	Correct	288 ms	8388 KB	Output is correct
16	Correct	171 ms	8324 KB	Output is correct
17	Correct	176 ms	8332 KB	Output is correct
18	Correct	171 ms	8308 KB	Output is correct
19	Correct	169 ms	8316 KB	Output is correct
20	Correct	159 ms	8308 KB	Output is correct

Subtask #2

22.0 / 22.0

#	결과	실행 시간	메모리	Grader output
1	Correct	288 ms	8364 KB	Output is correct
2	Correct	290 ms	8352 KB	Output is correct
3	Correct	286 ms	8352 KB	Output is correct
4	Correct	291 ms	8372 KB	Output is correct
5	Correct	300 ms	8268 KB	Output is correct
6	Correct	283 ms	8364 KB	Output is correct
7	Correct	296 ms	8356 KB	Output is correct
8	Correct	314 ms	8268 KB	Output is correct
9	Correct	300 ms	8268 KB	Output is correct
10	Correct	298 ms	8348 KB	Output is correct
11	Correct	295 ms	8356 KB	Output is correct
12	Correct	298 ms	8268 KB	Output is correct
13	Correct	295 ms	8352 KB	Output is correct
14	Correct	298 ms	8360 KB	Output is correct
15	Correct	288 ms	8388 KB	Output is correct
16	Correct	171 ms	8324 KB	Output is correct
17	Correct	176 ms	8332 KB	Output is correct
18	Correct	171 ms	8308 KB	Output is correct
19	Correct	169 ms	8316 KB	Output is correct
20	Correct	159 ms	8308 KB	Output is correct
21	Correct	325 ms	8344 KB	Output is correct
22	Correct	340 ms	8356 KB	Output is correct
23	Correct	351 ms	8360 KB	Output is correct
24	Correct	347 ms	8388 KB	Output is correct
25	Correct	336 ms	8268 KB	Output is correct
26	Correct	353 ms	8268 KB	Output is correct
27	Correct	356 ms	8352 KB	Output is correct
28	Correct	350 ms	8268 KB	Output is correct
29	Correct	343 ms	8352 KB	Output is correct
30	Correct	294 ms	8368 KB	Output is correct
31	Correct	295 ms	8368 KB	Output is correct
32	Correct	296 ms	8268 KB	Output is correct
33	Correct	291 ms	8420 KB	Output is correct
34	Correct	347 ms	8364 KB	Output is correct
35	Correct	301 ms	8276 KB	Output is correct
36	Correct	301 ms	8372 KB	Output is correct
37	Correct	286 ms	8268 KB	Output is correct
38	Correct	303 ms	8360 KB	Output is correct

Subtask #3

27.0 / 27.0

#	결과	실행 시간	메모리	Grader output
1	Correct	37 ms	8268 KB	Output is correct
2	Correct	37 ms	8268 KB	Output is correct
3	Correct	46 ms	8268 KB	Output is correct
4	Correct	42 ms	8268 KB	Output is correct
5	Correct	40 ms	8268 KB	Output is correct
6	Correct	38 ms	8268 KB	Output is correct
7	Correct	40 ms	8312 KB	Output is correct
8	Correct	41 ms	8268 KB	Output is correct
9	Correct	44 ms	8268 KB	Output is correct
10	Correct	45 ms	8204 KB	Output is correct
11	Correct	40 ms	8268 KB	Output is correct
12	Correct	52 ms	8312 KB	Output is correct
13	Correct	39 ms	8268 KB	Output is correct
14	Correct	38 ms	8268 KB	Output is correct
15	Correct	37 ms	8268 KB	Output is correct
16	Correct	49 ms	8268 KB	Output is correct
17	Correct	37 ms	8396 KB	Output is correct
18	Correct	46 ms	8268 KB	Output is correct
19	Correct	40 ms	8268 KB	Output is correct
20	Correct	36 ms	8308 KB	Output is correct

Subtask #4

42.0 / 42.0

#	결과	실행 시간	메모리	Grader output
1	Correct	288 ms	8364 KB	Output is correct
2	Correct	290 ms	8352 KB	Output is correct
3	Correct	286 ms	8352 KB	Output is correct
4	Correct	291 ms	8372 KB	Output is correct
5	Correct	300 ms	8268 KB	Output is correct
6	Correct	283 ms	8364 KB	Output is correct
7	Correct	296 ms	8356 KB	Output is correct
8	Correct	314 ms	8268 KB	Output is correct
9	Correct	300 ms	8268 KB	Output is correct
10	Correct	298 ms	8348 KB	Output is correct
11	Correct	295 ms	8356 KB	Output is correct
12	Correct	298 ms	8268 KB	Output is correct
13	Correct	295 ms	8352 KB	Output is correct
14	Correct	298 ms	8360 KB	Output is correct
15	Correct	288 ms	8388 KB	Output is correct
16	Correct	171 ms	8324 KB	Output is correct
17	Correct	176 ms	8332 KB	Output is correct
18	Correct	171 ms	8308 KB	Output is correct
19	Correct	169 ms	8316 KB	Output is correct
20	Correct	159 ms	8308 KB	Output is correct
21	Correct	325 ms	8344 KB	Output is correct
22	Correct	340 ms	8356 KB	Output is correct
23	Correct	351 ms	8360 KB	Output is correct
24	Correct	347 ms	8388 KB	Output is correct
25	Correct	336 ms	8268 KB	Output is correct
26	Correct	353 ms	8268 KB	Output is correct
27	Correct	356 ms	8352 KB	Output is correct
28	Correct	350 ms	8268 KB	Output is correct
29	Correct	343 ms	8352 KB	Output is correct
30	Correct	294 ms	8368 KB	Output is correct
31	Correct	295 ms	8368 KB	Output is correct
32	Correct	296 ms	8268 KB	Output is correct
33	Correct	291 ms	8420 KB	Output is correct
34	Correct	347 ms	8364 KB	Output is correct
35	Correct	301 ms	8276 KB	Output is correct
36	Correct	301 ms	8372 KB	Output is correct
37	Correct	286 ms	8268 KB	Output is correct
38	Correct	303 ms	8360 KB	Output is correct
39	Correct	37 ms	8268 KB	Output is correct
40	Correct	37 ms	8268 KB	Output is correct
41	Correct	46 ms	8268 KB	Output is correct
42	Correct	42 ms	8268 KB	Output is correct
43	Correct	40 ms	8268 KB	Output is correct
44	Correct	38 ms	8268 KB	Output is correct
45	Correct	40 ms	8312 KB	Output is correct
46	Correct	41 ms	8268 KB	Output is correct
47	Correct	44 ms	8268 KB	Output is correct
48	Correct	45 ms	8204 KB	Output is correct
49	Correct	40 ms	8268 KB	Output is correct
50	Correct	52 ms	8312 KB	Output is correct
51	Correct	39 ms	8268 KB	Output is correct
52	Correct	38 ms	8268 KB	Output is correct
53	Correct	37 ms	8268 KB	Output is correct
54	Correct	49 ms	8268 KB	Output is correct
55	Correct	37 ms	8396 KB	Output is correct
56	Correct	46 ms	8268 KB	Output is correct
57	Correct	40 ms	8268 KB	Output is correct
58	Correct	36 ms	8308 KB	Output is correct
59	Correct	889 ms	8360 KB	Output is correct
60	Correct	819 ms	8368 KB	Output is correct
61	Correct	810 ms	8388 KB	Output is correct
62	Correct	868 ms	8360 KB	Output is correct
63	Correct	834 ms	8376 KB	Output is correct
64	Correct	1110 ms	8388 KB	Output is correct
65	Correct	1133 ms	8364 KB	Output is correct
66	Correct	1121 ms	8368 KB	Output is correct
67	Correct	1127 ms	8360 KB	Output is correct
68	Correct	1126 ms	8368 KB	Output is correct
69	Correct	815 ms	8268 KB	Output is correct
70	Correct	808 ms	8388 KB	Output is correct
71	Correct	806 ms	8360 KB	Output is correct
72	Correct	819 ms	8360 KB	Output is correct
73	Correct	833 ms	8268 KB	Output is correct
74	Correct	230 ms	8268 KB	Output is correct
75	Correct	227 ms	8320 KB	Output is correct
76	Correct	253 ms	8320 KB	Output is correct
77	Correct	229 ms	8268 KB	Output is correct
78	Correct	235 ms	8320 KB	Output is correct