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답안 #110590

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
110590 2019-05-11T09:16:32 Z Pro_ktmr Boat (APIO16_boat) C++14
9 / 100
 2000 ms 8448 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 += tmp1 * 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);
	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:110:43: 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
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 8320 KB Output is correct
2 Correct 20 ms 8320 KB Output is correct
3 Correct 20 ms 8320 KB Output is correct
4 Correct 28 ms 8320 KB Output is correct
5 Correct 19 ms 8448 KB Output is correct
6 Correct 20 ms 8448 KB Output is correct
7 Correct 20 ms 8320 KB Output is correct
8 Correct 18 ms 8320 KB Output is correct
9 Correct 19 ms 8320 KB Output is correct
10 Correct 61 ms 8320 KB Output is correct
11 Correct 17 ms 8320 KB Output is correct
12 Correct 23 ms 8320 KB Output is correct
13 Correct 19 ms 8320 KB Output is correct
14 Correct 21 ms 8320 KB Output is correct
15 Correct 18 ms 8448 KB Output is correct
16 Correct 5 ms 1792 KB Output is correct
17 Correct 6 ms 1920 KB Output is correct
18 Correct 7 ms 1792 KB Output is correct
19 Correct 6 ms 1920 KB Output is correct
20 Correct 6 ms 1920 KB Output is correct

Subtask #2
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 8320 KB Output is correct
2 Correct 20 ms 8320 KB Output is correct
3 Correct 20 ms 8320 KB Output is correct
4 Correct 28 ms 8320 KB Output is correct
5 Correct 19 ms 8448 KB Output is correct
6 Correct 20 ms 8448 KB Output is correct
7 Correct 20 ms 8320 KB Output is correct
8 Correct 18 ms 8320 KB Output is correct
9 Correct 19 ms 8320 KB Output is correct
10 Correct 61 ms 8320 KB Output is correct
11 Correct 17 ms 8320 KB Output is correct
12 Correct 23 ms 8320 KB Output is correct
13 Correct 19 ms 8320 KB Output is correct
14 Correct 21 ms 8320 KB Output is correct
15 Correct 18 ms 8448 KB Output is correct
16 Correct 5 ms 1792 KB Output is correct
17 Correct 6 ms 1920 KB Output is correct
18 Correct 7 ms 1792 KB Output is correct
19 Correct 6 ms 1920 KB Output is correct
20 Correct 6 ms 1920 KB Output is correct
21 Execution timed out 2029 ms 8448 KB Time limit exceeded
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Correct 495 ms 1536 KB Output is correct
2 Correct 270 ms 1656 KB Output is correct
3 Correct 459 ms 1656 KB Output is correct
4 Correct 506 ms 1656 KB Output is correct
5 Correct 628 ms 1656 KB Output is correct
6 Execution timed out 2055 ms 1536 KB Time limit exceeded
7 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# 결과 실행 시간 메모리 Grader output
1 Correct 22 ms 8320 KB Output is correct
2 Correct 20 ms 8320 KB Output is correct
3 Correct 20 ms 8320 KB Output is correct
4 Correct 28 ms 8320 KB Output is correct
5 Correct 19 ms 8448 KB Output is correct
6 Correct 20 ms 8448 KB Output is correct
7 Correct 20 ms 8320 KB Output is correct
8 Correct 18 ms 8320 KB Output is correct
9 Correct 19 ms 8320 KB Output is correct
10 Correct 61 ms 8320 KB Output is correct
11 Correct 17 ms 8320 KB Output is correct
12 Correct 23 ms 8320 KB Output is correct
13 Correct 19 ms 8320 KB Output is correct
14 Correct 21 ms 8320 KB Output is correct
15 Correct 18 ms 8448 KB Output is correct
16 Correct 5 ms 1792 KB Output is correct
17 Correct 6 ms 1920 KB Output is correct
18 Correct 7 ms 1792 KB Output is correct
19 Correct 6 ms 1920 KB Output is correct
20 Correct 6 ms 1920 KB Output is correct
21 Execution timed out 2029 ms 8448 KB Time limit exceeded
22 Halted 0 ms 0 KB -