Submission #90538

# Submission time Handle Problem Language Result Execution time Memory
90538 2018-12-22T09:25:58 Z szawinis Boat (APIO16_boat) C++17
100 / 100
825 ms 25520 KB
#include <bits/stdc++.h>
using namespace std;
#define long long long
const long MOD = 1e9+7, LINF = 1e18 + 1e16;
const int INF = 1e9+1;
const double EPS = 1e-10;
const int dx[4] = {-1, 0, 1, 0}, dy[4] = {0, 1, 0, -1};
const int N = 1010;

class APIO16_boat {

	void add(long &a, long b) {
		a += b;
		if(a >= MOD) a -= MOD;
	}
	long mul(long a, long b) { return a*b % MOD; }
	long modPow(long b, long e) {
		if(e == 0) return 1;
		if(e == 1) return b;
		return mul(modPow(mul(b, b), e >> 1), modPow(b, e & 1));
	}

	int n, a[N], b[N];
	pair<int,int> segs[N];
	vector<int> vals;
	unordered_map<int, int> rev;

	long ans, inv[N], C[N][N], f[N][N], dp[N][N];

public:
	void solve(istream &cin, ostream &cout) {
		cin >> n;
		vals.push_back(0);
		for(int i = 1; i <= n; i++) {
			cin >> a[i] >> b[i];
			vals.push_back(a[i]);
			vals.push_back(b[i]+1);
		}
		sort(vals.begin(), vals.end());
		vals.resize(unique(vals.begin(), vals.end()) - vals.begin());
		for(int i = 0; i < vals.size(); i++) rev[vals[i]] = i;
		for(int i = 1; i <= n; i++) segs[i] = {rev[a[i]], rev[b[i]+1]};

		inv[0] = 1;
		for(int i = 1; i <= n; i++) inv[i] = modPow(i, MOD-2);
		C[0][0] = 1;
		for(int i = 1; i <= n; i++) {
			C[i][0] = C[i][i] = 1;
			for(int j = 1; j < i; j++) {
				add(C[i][j], C[i-1][j-1]);
				add(C[i][j], C[i-1][j]);
			}
		}

		for(int j = 1; j < vals.size()-1; j++) {
			f[j][0] = 1;
			for(int cnt = 1; cnt <= min(vals[j+1] - vals[j], n); cnt++) {
				f[j][cnt] = mul(f[j][cnt - 1], vals[j+1] - vals[j] - (cnt - 1));
				f[j][cnt] = mul(f[j][cnt], inv[cnt]);
			}
			for(int cnt = n; cnt >= 1; cnt--) {
				for(int x = 1; x <= min(cnt-1, n); x++) {
					add(f[j][cnt], mul(f[j][x], C[cnt-1][x-1]));
				}
			}
		}

		for(int j = 0; j < vals.size(); j++) dp[0][j] = 1;
		for(int i = 1; i <= n; i++) {
			for(int j = segs[i].first; j < segs[i].second; j++) {
				int cnt = 0;
				for(int k = i-1; k >= 0; k--) {
					cnt += segs[k+1].first <= j && j < segs[k+1].second;
					add(dp[i][j], mul(dp[k][j-1], f[j][cnt]));
				}
			}
			for(int j = 1; j < vals.size(); j++) add(dp[i][j], dp[i][j-1]);
			add(ans, dp[i][vals.size() - 1]);
		}
		cout << ans << endl;
	}
};

class Solver {
public:
	void solve(std::istream& in, std::ostream& out) {
	    APIO16_boat *obj = new APIO16_boat();
		obj->solve(in, out);
		delete obj;
	}
};

int main() {
	ios::sync_with_stdio(false);
	cin.tie(0);
	Solver solver;
	std::istream& in(std::cin);
	std::ostream& out(std::cout);
	solver.solve(in, out);
	return 0;
}

Compilation message

boat.cpp: In member function 'void APIO16_boat::solve(std::istream&, std::ostream&)':
boat.cpp:41:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int i = 0; i < vals.size(); i++) rev[vals[i]] = i;
                  ~~^~~~~~~~~~~~~
boat.cpp:55:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = 1; j < vals.size()-1; j++) {
                  ~~^~~~~~~~~~~~~~~
boat.cpp:68:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j = 0; j < vals.size(); j++) dp[0][j] = 1;
                  ~~^~~~~~~~~~~~~
boat.cpp:77:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int j = 1; j < vals.size(); j++) add(dp[i][j], dp[i][j-1]);
                   ~~^~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 463 ms 24440 KB Output is correct
2 Correct 459 ms 24700 KB Output is correct
3 Correct 448 ms 24700 KB Output is correct
4 Correct 440 ms 24700 KB Output is correct
5 Correct 472 ms 24700 KB Output is correct
6 Correct 441 ms 24736 KB Output is correct
7 Correct 459 ms 24736 KB Output is correct
8 Correct 436 ms 24736 KB Output is correct
9 Correct 458 ms 24736 KB Output is correct
10 Correct 453 ms 24972 KB Output is correct
11 Correct 455 ms 24972 KB Output is correct
12 Correct 448 ms 24972 KB Output is correct
13 Correct 458 ms 24972 KB Output is correct
14 Correct 462 ms 24972 KB Output is correct
15 Correct 474 ms 24972 KB Output is correct
16 Correct 98 ms 24972 KB Output is correct
17 Correct 102 ms 24972 KB Output is correct
18 Correct 99 ms 24972 KB Output is correct
19 Correct 105 ms 25080 KB Output is correct
20 Correct 99 ms 25080 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 463 ms 24440 KB Output is correct
2 Correct 459 ms 24700 KB Output is correct
3 Correct 448 ms 24700 KB Output is correct
4 Correct 440 ms 24700 KB Output is correct
5 Correct 472 ms 24700 KB Output is correct
6 Correct 441 ms 24736 KB Output is correct
7 Correct 459 ms 24736 KB Output is correct
8 Correct 436 ms 24736 KB Output is correct
9 Correct 458 ms 24736 KB Output is correct
10 Correct 453 ms 24972 KB Output is correct
11 Correct 455 ms 24972 KB Output is correct
12 Correct 448 ms 24972 KB Output is correct
13 Correct 458 ms 24972 KB Output is correct
14 Correct 462 ms 24972 KB Output is correct
15 Correct 474 ms 24972 KB Output is correct
16 Correct 98 ms 24972 KB Output is correct
17 Correct 102 ms 24972 KB Output is correct
18 Correct 99 ms 24972 KB Output is correct
19 Correct 105 ms 25080 KB Output is correct
20 Correct 99 ms 25080 KB Output is correct
21 Correct 587 ms 25080 KB Output is correct
22 Correct 612 ms 25080 KB Output is correct
23 Correct 607 ms 25080 KB Output is correct
24 Correct 624 ms 25080 KB Output is correct
25 Correct 588 ms 25080 KB Output is correct
26 Correct 674 ms 25080 KB Output is correct
27 Correct 712 ms 25080 KB Output is correct
28 Correct 673 ms 25088 KB Output is correct
29 Correct 674 ms 25096 KB Output is correct
30 Correct 439 ms 25104 KB Output is correct
31 Correct 452 ms 25104 KB Output is correct
32 Correct 450 ms 25180 KB Output is correct
33 Correct 450 ms 25184 KB Output is correct
34 Correct 458 ms 25184 KB Output is correct
35 Correct 452 ms 25208 KB Output is correct
36 Correct 442 ms 25348 KB Output is correct
37 Correct 456 ms 25348 KB Output is correct
38 Correct 445 ms 25348 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 26 ms 25348 KB Output is correct
2 Correct 26 ms 25348 KB Output is correct
3 Correct 26 ms 25348 KB Output is correct
4 Correct 26 ms 25348 KB Output is correct
5 Correct 26 ms 25348 KB Output is correct
6 Correct 27 ms 25348 KB Output is correct
7 Correct 24 ms 25348 KB Output is correct
8 Correct 27 ms 25348 KB Output is correct
9 Correct 24 ms 25348 KB Output is correct
10 Correct 24 ms 25348 KB Output is correct
11 Correct 27 ms 25348 KB Output is correct
12 Correct 25 ms 25348 KB Output is correct
13 Correct 26 ms 25348 KB Output is correct
14 Correct 26 ms 25348 KB Output is correct
15 Correct 26 ms 25348 KB Output is correct
16 Correct 24 ms 25348 KB Output is correct
17 Correct 24 ms 25348 KB Output is correct
18 Correct 24 ms 25348 KB Output is correct
19 Correct 23 ms 25348 KB Output is correct
20 Correct 25 ms 25348 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 463 ms 24440 KB Output is correct
2 Correct 459 ms 24700 KB Output is correct
3 Correct 448 ms 24700 KB Output is correct
4 Correct 440 ms 24700 KB Output is correct
5 Correct 472 ms 24700 KB Output is correct
6 Correct 441 ms 24736 KB Output is correct
7 Correct 459 ms 24736 KB Output is correct
8 Correct 436 ms 24736 KB Output is correct
9 Correct 458 ms 24736 KB Output is correct
10 Correct 453 ms 24972 KB Output is correct
11 Correct 455 ms 24972 KB Output is correct
12 Correct 448 ms 24972 KB Output is correct
13 Correct 458 ms 24972 KB Output is correct
14 Correct 462 ms 24972 KB Output is correct
15 Correct 474 ms 24972 KB Output is correct
16 Correct 98 ms 24972 KB Output is correct
17 Correct 102 ms 24972 KB Output is correct
18 Correct 99 ms 24972 KB Output is correct
19 Correct 105 ms 25080 KB Output is correct
20 Correct 99 ms 25080 KB Output is correct
21 Correct 587 ms 25080 KB Output is correct
22 Correct 612 ms 25080 KB Output is correct
23 Correct 607 ms 25080 KB Output is correct
24 Correct 624 ms 25080 KB Output is correct
25 Correct 588 ms 25080 KB Output is correct
26 Correct 674 ms 25080 KB Output is correct
27 Correct 712 ms 25080 KB Output is correct
28 Correct 673 ms 25088 KB Output is correct
29 Correct 674 ms 25096 KB Output is correct
30 Correct 439 ms 25104 KB Output is correct
31 Correct 452 ms 25104 KB Output is correct
32 Correct 450 ms 25180 KB Output is correct
33 Correct 450 ms 25184 KB Output is correct
34 Correct 458 ms 25184 KB Output is correct
35 Correct 452 ms 25208 KB Output is correct
36 Correct 442 ms 25348 KB Output is correct
37 Correct 456 ms 25348 KB Output is correct
38 Correct 445 ms 25348 KB Output is correct
39 Correct 26 ms 25348 KB Output is correct
40 Correct 26 ms 25348 KB Output is correct
41 Correct 26 ms 25348 KB Output is correct
42 Correct 26 ms 25348 KB Output is correct
43 Correct 26 ms 25348 KB Output is correct
44 Correct 27 ms 25348 KB Output is correct
45 Correct 24 ms 25348 KB Output is correct
46 Correct 27 ms 25348 KB Output is correct
47 Correct 24 ms 25348 KB Output is correct
48 Correct 24 ms 25348 KB Output is correct
49 Correct 27 ms 25348 KB Output is correct
50 Correct 25 ms 25348 KB Output is correct
51 Correct 26 ms 25348 KB Output is correct
52 Correct 26 ms 25348 KB Output is correct
53 Correct 26 ms 25348 KB Output is correct
54 Correct 24 ms 25348 KB Output is correct
55 Correct 24 ms 25348 KB Output is correct
56 Correct 24 ms 25348 KB Output is correct
57 Correct 23 ms 25348 KB Output is correct
58 Correct 25 ms 25348 KB Output is correct
59 Correct 690 ms 25348 KB Output is correct
60 Correct 674 ms 25348 KB Output is correct
61 Correct 648 ms 25420 KB Output is correct
62 Correct 720 ms 25420 KB Output is correct
63 Correct 703 ms 25420 KB Output is correct
64 Correct 812 ms 25420 KB Output is correct
65 Correct 825 ms 25420 KB Output is correct
66 Correct 803 ms 25420 KB Output is correct
67 Correct 790 ms 25420 KB Output is correct
68 Correct 805 ms 25420 KB Output is correct
69 Correct 611 ms 25520 KB Output is correct
70 Correct 655 ms 25520 KB Output is correct
71 Correct 618 ms 25520 KB Output is correct
72 Correct 622 ms 25520 KB Output is correct
73 Correct 661 ms 25520 KB Output is correct
74 Correct 139 ms 25520 KB Output is correct
75 Correct 140 ms 25520 KB Output is correct
76 Correct 136 ms 25520 KB Output is correct
77 Correct 154 ms 25520 KB Output is correct
78 Correct 143 ms 25520 KB Output is correct