oj.uz

Submission #259054

# Submission time Handle Problem Language Result Execution time Memory
259054 2020-08-07T05:30:28 Z ChrisT Boat (APIO16_boat) C++17
100 / 100
 1133 ms 11512 KB 
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using pii = pair<int,int>;
const int MN = 505, LOG = 18, MOD = 1e9 + 7;
int dp[MN][MN<<1],pre[MN<<1][MN][2],a[MN],b[MN];
int ch[MN][MN], ch2[MN<<1][MN][2], iv[MN<<1];
int inv (int base) {
	int res = 1, exp = MOD - 2;
	while (exp) {
		if (exp&1) res = (ll)res * base % MOD;
		base = (ll)base * base % MOD;
		exp>>=1;
	}
	return res;
}
int choose (int n, int k) {
	assert(n >= 0 && k >= 0);
	int res = 1;
	for (int i = n; i > n-k; i--) res = (ll)res * i % MOD;
	for (int i = 2; i <= k; i++) res = (ll)res * iv[i] % MOD;
	return res;
}
int calc (int j, int x, bool ree) {
	int ret = ch2[j][x-ree][ree];
	for (int zeros = 1; zeros <= x-2; zeros++) ret = (ret + (ll)ch2[j][x-zeros-ree][ree] * ch[x-2][zeros]) % MOD;
	return ret;
}
int main () {
	int n;
	scanf ("%d",&n);
	for (int i = 0; i <= n*2; i++) iv[i] = inv(i);
	for (int i = 0; i <= n; i++) for (int j = 0; j <= i; j++) ch[i][j] = choose(i,j);
	vector<int> xs = {-1};
	for (int i = 1; i <= n; i++) {
		scanf ("%d %d",&a[i],&b[i]);
		xs.push_back(a[i]); xs.push_back(b[i]);
	}
	sort(xs.begin(),xs.end()); xs.erase(unique(xs.begin(),xs.end()),xs.end());
	int m = xs.size() - 1;
	for (int j = 1; j <= m; j++) {
		ch2[j][0][0] = ch2[j][0][1] = 1;
		for (int i = 1; i <= n; i++) {
			ch2[j][i][0] = (ll)ch2[j][i-1][0] * (xs[j]-xs[j-1]-i+1) % MOD * inv(i) % MOD;
			ch2[j][i][1] = (ll)ch2[j][i-1][1] * (xs[j]-xs[j-1]-i) % MOD * inv(i) % MOD;
		}
	}
	memset(pre,-1,sizeof pre);
	for (int j = 0; j <= m; j++) dp[0][j] = 1;
	for (int i = 1; i <= n; i++) {
		for (int j = 0; j <= m; j++){
			if (j) dp[i][j] = (dp[i][j] + dp[i][j-1]) % MOD;
			if (xs[j] < a[i] || (j&&b[i] <= xs[j-1])) continue;
			bool ree = a[i]==xs[j]; int cnt = 0;
			for (int k = i; k >= 1; k--) {
				if (a[k] > xs[j] || b[k] <= xs[j-1] || (k!=i&&a[k]==xs[j])) continue;
				++cnt;
				if (!~pre[j][cnt][ree]) pre[j][cnt][ree] = calc(j,cnt,ree);
				dp[i][j] = (dp[i][j] + (ll)dp[k-1][j-1] * pre[j][cnt][ree]) % MOD;
			}
		}
		for (int j = 0; j <= m; j++) {
			dp[i][j] = (dp[i][j] + dp[i-1][j]) % MOD;
		}
	}
	printf ("%d\n",(dp[n][m] + MOD - 1) % MOD);
	return 0;
}

Compilation message

boat.cpp: In function 'int main()':
boat.cpp:31:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf ("%d",&n);
  ~~~~~~^~~~~~~~~
boat.cpp:36:9: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf ("%d %d",&a[i],&b[i]);
   ~~~~~~^~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 335 ms 9208 KB Output is correct
2 Correct 335 ms 9464 KB Output is correct
3 Correct 336 ms 9248 KB Output is correct
4 Correct 337 ms 9464 KB Output is correct
5 Correct 337 ms 9208 KB Output is correct
6 Correct 331 ms 9312 KB Output is correct
7 Correct 335 ms 9208 KB Output is correct
8 Correct 334 ms 9336 KB Output is correct
9 Correct 335 ms 9208 KB Output is correct
10 Correct 336 ms 9208 KB Output is correct
11 Correct 335 ms 9228 KB Output is correct
12 Correct 335 ms 9208 KB Output is correct
13 Correct 334 ms 9296 KB Output is correct
14 Correct 337 ms 9336 KB Output is correct
15 Correct 334 ms 9212 KB Output is correct
16 Correct 257 ms 7800 KB Output is correct
17 Correct 256 ms 7672 KB Output is correct
18 Correct 258 ms 7764 KB Output is correct
19 Correct 256 ms 7672 KB Output is correct
20 Correct 258 ms 7800 KB Output is correct

Subtask #2
22.0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 335 ms 9208 KB Output is correct
2 Correct 335 ms 9464 KB Output is correct
3 Correct 336 ms 9248 KB Output is correct
4 Correct 337 ms 9464 KB Output is correct
5 Correct 337 ms 9208 KB Output is correct
6 Correct 331 ms 9312 KB Output is correct
7 Correct 335 ms 9208 KB Output is correct
8 Correct 334 ms 9336 KB Output is correct
9 Correct 335 ms 9208 KB Output is correct
10 Correct 336 ms 9208 KB Output is correct
11 Correct 335 ms 9228 KB Output is correct
12 Correct 335 ms 9208 KB Output is correct
13 Correct 334 ms 9296 KB Output is correct
14 Correct 337 ms 9336 KB Output is correct
15 Correct 334 ms 9212 KB Output is correct
16 Correct 257 ms 7800 KB Output is correct
17 Correct 256 ms 7672 KB Output is correct
18 Correct 258 ms 7764 KB Output is correct
19 Correct 256 ms 7672 KB Output is correct
20 Correct 258 ms 7800 KB Output is correct
21 Correct 676 ms 10892 KB Output is correct
22 Correct 675 ms 10872 KB Output is correct
23 Correct 639 ms 10872 KB Output is correct
24 Correct 666 ms 11000 KB Output is correct
25 Correct 667 ms 10872 KB Output is correct
26 Correct 1004 ms 10868 KB Output is correct
27 Correct 1016 ms 10844 KB Output is correct
28 Correct 1016 ms 10872 KB Output is correct
29 Correct 979 ms 10748 KB Output is correct
30 Correct 424 ms 11264 KB Output is correct
31 Correct 424 ms 11132 KB Output is correct
32 Correct 417 ms 11000 KB Output is correct
33 Correct 418 ms 11000 KB Output is correct
34 Correct 419 ms 11128 KB Output is correct
35 Correct 333 ms 9336 KB Output is correct
36 Correct 337 ms 9336 KB Output is correct
37 Correct 336 ms 9468 KB Output is correct
38 Correct 336 ms 9292 KB Output is correct

Subtask #3
27.0 / 27.0

# Verdict Execution time Memory Grader output
1 Correct 14 ms 5760 KB Output is correct
2 Correct 14 ms 5760 KB Output is correct
3 Correct 15 ms 5680 KB Output is correct
4 Correct 18 ms 5752 KB Output is correct
5 Correct 16 ms 5760 KB Output is correct
6 Correct 20 ms 5756 KB Output is correct
7 Correct 19 ms 5760 KB Output is correct
8 Correct 18 ms 5752 KB Output is correct
9 Correct 18 ms 5760 KB Output is correct
10 Correct 18 ms 5760 KB Output is correct
11 Correct 15 ms 5760 KB Output is correct
12 Correct 15 ms 5760 KB Output is correct
13 Correct 15 ms 5760 KB Output is correct
14 Correct 18 ms 5760 KB Output is correct
15 Correct 15 ms 5760 KB Output is correct
16 Correct 10 ms 5248 KB Output is correct
17 Correct 9 ms 5248 KB Output is correct
18 Correct 9 ms 5248 KB Output is correct
19 Correct 10 ms 5300 KB Output is correct
20 Correct 12 ms 5248 KB Output is correct

Subtask #4
42.0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 335 ms 9208 KB Output is correct
2 Correct 335 ms 9464 KB Output is correct
3 Correct 336 ms 9248 KB Output is correct
4 Correct 337 ms 9464 KB Output is correct
5 Correct 337 ms 9208 KB Output is correct
6 Correct 331 ms 9312 KB Output is correct
7 Correct 335 ms 9208 KB Output is correct
8 Correct 334 ms 9336 KB Output is correct
9 Correct 335 ms 9208 KB Output is correct
10 Correct 336 ms 9208 KB Output is correct
11 Correct 335 ms 9228 KB Output is correct
12 Correct 335 ms 9208 KB Output is correct
13 Correct 334 ms 9296 KB Output is correct
14 Correct 337 ms 9336 KB Output is correct
15 Correct 334 ms 9212 KB Output is correct
16 Correct 257 ms 7800 KB Output is correct
17 Correct 256 ms 7672 KB Output is correct
18 Correct 258 ms 7764 KB Output is correct
19 Correct 256 ms 7672 KB Output is correct
20 Correct 258 ms 7800 KB Output is correct
21 Correct 676 ms 10892 KB Output is correct
22 Correct 675 ms 10872 KB Output is correct
23 Correct 639 ms 10872 KB Output is correct
24 Correct 666 ms 11000 KB Output is correct
25 Correct 667 ms 10872 KB Output is correct
26 Correct 1004 ms 10868 KB Output is correct
27 Correct 1016 ms 10844 KB Output is correct
28 Correct 1016 ms 10872 KB Output is correct
29 Correct 979 ms 10748 KB Output is correct
30 Correct 424 ms 11264 KB Output is correct
31 Correct 424 ms 11132 KB Output is correct
32 Correct 417 ms 11000 KB Output is correct
33 Correct 418 ms 11000 KB Output is correct
34 Correct 419 ms 11128 KB Output is correct
35 Correct 333 ms 9336 KB Output is correct
36 Correct 337 ms 9336 KB Output is correct
37 Correct 336 ms 9468 KB Output is correct
38 Correct 336 ms 9292 KB Output is correct
39 Correct 14 ms 5760 KB Output is correct
40 Correct 14 ms 5760 KB Output is correct
41 Correct 15 ms 5680 KB Output is correct
42 Correct 18 ms 5752 KB Output is correct
43 Correct 16 ms 5760 KB Output is correct
44 Correct 20 ms 5756 KB Output is correct
45 Correct 19 ms 5760 KB Output is correct
46 Correct 18 ms 5752 KB Output is correct
47 Correct 18 ms 5760 KB Output is correct
48 Correct 18 ms 5760 KB Output is correct
49 Correct 15 ms 5760 KB Output is correct
50 Correct 15 ms 5760 KB Output is correct
51 Correct 15 ms 5760 KB Output is correct
52 Correct 18 ms 5760 KB Output is correct
53 Correct 15 ms 5760 KB Output is correct
54 Correct 10 ms 5248 KB Output is correct
55 Correct 9 ms 5248 KB Output is correct
56 Correct 9 ms 5248 KB Output is correct
57 Correct 10 ms 5300 KB Output is correct
58 Correct 12 ms 5248 KB Output is correct
59 Correct 703 ms 11256 KB Output is correct
60 Correct 681 ms 11388 KB Output is correct
61 Correct 666 ms 11384 KB Output is correct
62 Correct 721 ms 11256 KB Output is correct
63 Correct 695 ms 11384 KB Output is correct
64 Correct 1090 ms 11384 KB Output is correct
65 Correct 1102 ms 11400 KB Output is correct
66 Correct 1102 ms 11236 KB Output is correct
67 Correct 1094 ms 11236 KB Output is correct
68 Correct 1133 ms 11512 KB Output is correct
69 Correct 676 ms 11404 KB Output is correct
70 Correct 676 ms 11256 KB Output is correct
71 Correct 675 ms 11256 KB Output is correct
72 Correct 685 ms 11256 KB Output is correct
73 Correct 688 ms 11256 KB Output is correct
74 Correct 293 ms 7672 KB Output is correct
75 Correct 294 ms 7796 KB Output is correct
76 Correct 292 ms 7676 KB Output is correct
77 Correct 306 ms 7800 KB Output is correct
78 Correct 297 ms 7724 KB Output is correct