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Submission #110588

# Submission time Handle Problem Language Result Execution time Memory
110588 2019-05-11T09:12:36 Z Pro_ktmr Boat (APIO16_boat) C++14
0 / 100
 507 ms 8508 KB 
#include"bits/stdc++.h"
using namespace std;
#define LL long long
#define PB push_back
#define MP make_pair

const LL MOD = 1000000007;

//累乗 O(log N)
long long power(long long x, int N){
	if(N == 1) return x;
	long long tmp = power(x, N/2);
	if(N%2 == 0) return tmp * tmp % MOD;
	else return tmp * tmp % MOD * x % MOD;
}

//逆元 O(log x)
long long inverse(long long x){
	return power(x, MOD-2);
}

//コンビネーション
struct Combination{
private:
	int N;
	vector<long long> fact, inv;
public:
	void init(int n){ //初期化する O(N)
		N = n;
		fact.push_back(1);
		inv.push_back(1);
		for(long long i=1; i<=N; i++){
			fact.push_back(fact.back()*i%MOD);
			inv.push_back(inverse(fact.back()));
		}
	}
	long long comb(int n, int k){ //nCkを求める O(1)
		return fact[n] * inv[k] % MOD * inv[n-k] % MOD;
	}
};

Combination comb;

int N, a[500], b[500], A[500], B[500];
vector<int> v;
vector<int> ls[1000];

LL culc(LL range, int num){
	if(num == 1) return range;
	LL ret = 0;
	LL tmp1 = range;
	LL tmp2 = range-1;
	for(int i=0; i<=num-2; i++){ //中のを何個使うか
		if(tmp2 == 0) break;
		tmp1 = tmp1 * tmp2 % MOD;
		tmp1 = tmp1 * inverse(i+2) % MOD;
		tmp2--;
		ret += tmp2 * comb.comb(num-2, i) % MOD;
	}
	return ret % MOD;
}

//a:=区間、b:=学校
LL dp[1000][500][2];
LL solve(int a, int b, int ok){
	if(a == v.size()-1) return 1;
	if(ok == 0 && b == N) return 0;
	if(ok == 1 && b == N) return 1;
	if(dp[a][b][ok] != -1) return dp[a][b][ok];
	if(ok == 0){
		dp[a][b][ok] = solve(a, b+1, 0);
		if(A[b] <= a && a < B[b]){
			int idx = lower_bound(ls[a].begin(), ls[a].end(), b) - ls[a].begin();
			LL range = v[a+1] - v[a];
			for(int i=idx; i<ls[a].size()-1; i++){
				dp[a][b][ok] += culc(range, i-idx+1)*solve(a+1, ls[a][i]+1, 1);
				dp[a][b][ok] %= MOD;
			}
		}
	}
	else{
		dp[a][b][ok] = solve(a+1, b, 1);
		dp[a][b][ok] += solve(a, b, 0);
		dp[a][b][ok] %= MOD;
	}
	return dp[a][b][ok];
}

int main(){
	scanf("%d", &N);
	for(int i=0; i<N; i++){
		scanf("%d%d", a+i, b+i);
		b[i]++;
		v.PB(a[i]);
		v.PB(b[i]);
	}
	sort(v.begin(), v.end());
	v.erase(unique(v.begin(), v.end()), v.end());
	for(int i=0; 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]) - v.begin();
		for(int j=A[i]; j<B[i]; j++) ls[j].PB(i);
	}
	for(int i=0; i<v.size(); i++){
		ls[i].PB(N);
		for(int j=0; j<N; j++) dp[i][j][0] = -1;
		for(int j=0; j<N; j++) dp[i][j][1] = -1;
	}
	comb.init(N);
	if(v.size() != 2*N) assert(false);
	printf("%d\n", (solve(0, 0, 1)-1+MOD)%MOD);
}

Compilation message

boat.cpp: In function 'long long int solve(int, int, int)':
boat.cpp:66:7: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(a == v.size()-1) return 1;
     ~~^~~~~~~~~~~~~
boat.cpp:75:20: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int i=idx; i<ls[a].size()-1; i++){
                   ~^~~~~~~~~~~~~~~
boat.cpp: In function 'int main()':
boat.cpp:104:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<v.size(); i++){
               ~^~~~~~~~~
boat.cpp:110:14: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if(v.size() != 2*N) assert(false);
     ~~~~~~~~~^~~~~~
boat.cpp:111:43: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
  printf("%d\n", (solve(0, 0, 1)-1+MOD)%MOD);
                 ~~~~~~~~~~~~~~~~~~~~~~~~~~^
boat.cpp:90:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
boat.cpp:92:8: 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
0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 8440 KB Output is correct
2 Correct 21 ms 8320 KB Output is correct
3 Correct 21 ms 8320 KB Output is correct
4 Correct 29 ms 8320 KB Output is correct
5 Correct 20 ms 8320 KB Output is correct
6 Correct 17 ms 8320 KB Output is correct
7 Correct 19 ms 8320 KB Output is correct
8 Correct 24 ms 8440 KB Output is correct
9 Correct 23 ms 8320 KB Output is correct
10 Correct 20 ms 8508 KB Output is correct
11 Correct 20 ms 8448 KB Output is correct
12 Correct 20 ms 8312 KB Output is correct
13 Correct 20 ms 8320 KB Output is correct
14 Correct 19 ms 8320 KB Output is correct
15 Correct 19 ms 8320 KB Output is correct
16 Runtime error 6 ms 3456 KB Execution killed with signal 11 (could be triggered by violating memory limits)
17 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 8440 KB Output is correct
2 Correct 21 ms 8320 KB Output is correct
3 Correct 21 ms 8320 KB Output is correct
4 Correct 29 ms 8320 KB Output is correct
5 Correct 20 ms 8320 KB Output is correct
6 Correct 17 ms 8320 KB Output is correct
7 Correct 19 ms 8320 KB Output is correct
8 Correct 24 ms 8440 KB Output is correct
9 Correct 23 ms 8320 KB Output is correct
10 Correct 20 ms 8508 KB Output is correct
11 Correct 20 ms 8448 KB Output is correct
12 Correct 20 ms 8312 KB Output is correct
13 Correct 20 ms 8320 KB Output is correct
14 Correct 19 ms 8320 KB Output is correct
15 Correct 19 ms 8320 KB Output is correct
16 Runtime error 6 ms 3456 KB Execution killed with signal 11 (could be triggered by violating memory limits)
17 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 507 ms 1592 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 21 ms 8440 KB Output is correct
2 Correct 21 ms 8320 KB Output is correct
3 Correct 21 ms 8320 KB Output is correct
4 Correct 29 ms 8320 KB Output is correct
5 Correct 20 ms 8320 KB Output is correct
6 Correct 17 ms 8320 KB Output is correct
7 Correct 19 ms 8320 KB Output is correct
8 Correct 24 ms 8440 KB Output is correct
9 Correct 23 ms 8320 KB Output is correct
10 Correct 20 ms 8508 KB Output is correct
11 Correct 20 ms 8448 KB Output is correct
12 Correct 20 ms 8312 KB Output is correct
13 Correct 20 ms 8320 KB Output is correct
14 Correct 19 ms 8320 KB Output is correct
15 Correct 19 ms 8320 KB Output is correct
16 Runtime error 6 ms 3456 KB Execution killed with signal 11 (could be triggered by violating memory limits)
17 Halted 0 ms 0 KB -