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답안 #110594

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
110594 2019-05-11T09:31:10 Z Pro_ktmr Boat (APIO16_boat) C++14
9 / 100
 29 ms 12288 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 memo[1000][501];
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();
			for(int i=idx; i<ls[a].size()-1; i++){
				dp[a][b][ok] += memo[a][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;
		if(i != v.size()-1) for(int j=1; j<=ls[i].size(); j++) memo[i][j] = culc(v[i+1]-v[i], j);
	}
	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:67:7: 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:108:8: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i != v.size()-1) for(int j=1; j<=ls[i].size(); j++) memo[i][j] = culc(v[i+1]-v[i], j);
      ~~^~~~~~~~~~~~~
boat.cpp:108:37: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   if(i != v.size()-1) for(int j=1; j<=ls[i].size(); j++) memo[i][j] = culc(v[i+1]-v[i], j);
                                    ~^~~~~~~~~~~~~~
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
9.0 / 9.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 12288 KB Output is correct
2 Correct 28 ms 12280 KB Output is correct
3 Correct 26 ms 12288 KB Output is correct
4 Correct 26 ms 12288 KB Output is correct
5 Correct 29 ms 12288 KB Output is correct
6 Correct 22 ms 12288 KB Output is correct
7 Correct 21 ms 12288 KB Output is correct
8 Correct 22 ms 12288 KB Output is correct
9 Correct 25 ms 12288 KB Output is correct
10 Correct 26 ms 12288 KB Output is correct
11 Correct 21 ms 12204 KB Output is correct
12 Correct 24 ms 12288 KB Output is correct
13 Correct 21 ms 12288 KB Output is correct
14 Correct 26 ms 12288 KB Output is correct
15 Correct 27 ms 12288 KB Output is correct
16 Correct 6 ms 2560 KB Output is correct
17 Correct 9 ms 2688 KB Output is correct
18 Correct 8 ms 2560 KB Output is correct
19 Correct 6 ms 2688 KB Output is correct
20 Correct 6 ms 2560 KB Output is correct

Subtask #2
0 / 22.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 12288 KB Output is correct
2 Correct 28 ms 12280 KB Output is correct
3 Correct 26 ms 12288 KB Output is correct
4 Correct 26 ms 12288 KB Output is correct
5 Correct 29 ms 12288 KB Output is correct
6 Correct 22 ms 12288 KB Output is correct
7 Correct 21 ms 12288 KB Output is correct
8 Correct 22 ms 12288 KB Output is correct
9 Correct 25 ms 12288 KB Output is correct
10 Correct 26 ms 12288 KB Output is correct
11 Correct 21 ms 12204 KB Output is correct
12 Correct 24 ms 12288 KB Output is correct
13 Correct 21 ms 12288 KB Output is correct
14 Correct 26 ms 12288 KB Output is correct
15 Correct 27 ms 12288 KB Output is correct
16 Correct 6 ms 2560 KB Output is correct
17 Correct 9 ms 2688 KB Output is correct
18 Correct 8 ms 2560 KB Output is correct
19 Correct 6 ms 2688 KB Output is correct
20 Correct 6 ms 2560 KB Output is correct
21 Runtime error 6 ms 2304 KB Execution killed with signal 11 (could be triggered by violating memory limits)
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# 결과 실행 시간 메모리 Grader output
1 Runtime error 3 ms 640 KB Execution killed with signal 11 (could be triggered by violating memory limits)
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# 결과 실행 시간 메모리 Grader output
1 Correct 23 ms 12288 KB Output is correct
2 Correct 28 ms 12280 KB Output is correct
3 Correct 26 ms 12288 KB Output is correct
4 Correct 26 ms 12288 KB Output is correct
5 Correct 29 ms 12288 KB Output is correct
6 Correct 22 ms 12288 KB Output is correct
7 Correct 21 ms 12288 KB Output is correct
8 Correct 22 ms 12288 KB Output is correct
9 Correct 25 ms 12288 KB Output is correct
10 Correct 26 ms 12288 KB Output is correct
11 Correct 21 ms 12204 KB Output is correct
12 Correct 24 ms 12288 KB Output is correct
13 Correct 21 ms 12288 KB Output is correct
14 Correct 26 ms 12288 KB Output is correct
15 Correct 27 ms 12288 KB Output is correct
16 Correct 6 ms 2560 KB Output is correct
17 Correct 9 ms 2688 KB Output is correct
18 Correct 8 ms 2560 KB Output is correct
19 Correct 6 ms 2688 KB Output is correct
20 Correct 6 ms 2560 KB Output is correct
21 Runtime error 6 ms 2304 KB Execution killed with signal 11 (could be triggered by violating memory limits)
22 Halted 0 ms 0 KB -