oj.uz

Submission #145470

# Submission time Handle Problem Language Result Execution time Memory
145470 2019-08-20T04:30:59 Z arnold518 Boat (APIO16_boat) C++14
0 / 100
 48 ms 8316 KB 
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const int MAXN = 500;
const ll MOD = 1e9+7;

int N, A[MAXN+10], B[MAXN+10];
vector<int> comp;
ll dp[MAXN+10][MAXN*2+10], psum[MAXN+10][MAXN*2+10], cnt[MAXN*2+10], val[MAXN*2+10];

int getcomp(int x) { return lower_bound(comp.begin(), comp.end(), x)-comp.begin()+1; }

ll mypow(ll x, ll y)
{
	if(y==0) return 1;
	if(y%2) return mypow(x, y-1)*x%MOD;
	ll ret=mypow(x, y/2);
	return ret*ret%MOD;
}	
ll inv(ll x) { return mypow(x, MOD-2); }

ll comb(ll n, ll r)
{
	ll i, j;
	r=min(r, n-r);
	ll ret=1;
	for(i=1; i<=r; i++) ret=ret*inv(i)%MOD*(n-i+1)%MOD;
	return ret;
}
ll f(ll i, ll j) { return (comb(i+j-1, i)+MOD-1)%MOD; }

int main()
{
	int i, j;
	
	scanf("%d", &N);
	for(i=1; i<=N; i++) scanf("%d%d", &A[i], &B[i]), B[i]++, comp.push_back(A[i]), comp.push_back(B[i]);
	sort(comp.begin(), comp.end());
	comp.erase(unique(comp.begin(), comp.end()), comp.end());

	dp[0][0]=1;
	for(j=0; j<comp.size(); j++) psum[0][j]=1;
	for(i=1; i<=N; i++)
	{
		for(j=0; j<comp.size(); j++)
		{
			if(!(getcomp(A[i])<=j && j<getcomp(B[i]))) { dp[i][j]=dp[i-1][j]; continue; }
			cnt[j]++;
			if(cnt[j]==1)
			{
				val[j]=psum[i-1][j-1];
				dp[i][j]+=psum[i-1][j-1]*(comp[j]-comp[j-1])%MOD;
			}
			else
			{
				dp[i][j]+=((psum[i-1][j-1]-val[j])*(comp[j]-comp[j-1])%MOD+val[j]*f(cnt[j], comp[j]-comp[j-1]+1)%MOD)%MOD;
			}
			dp[i][j]%=MOD;
		}
		//for(j=0; j<comp.size(); j++) printf("%lld ", dp[i][j]); printf("\n");
		psum[i][0]=dp[i][0];
		for(j=1; j<comp.size(); j++) psum[i][j]=(dp[i][j]+psum[i][j-1])%MOD;
	}
	printf("%lld", (psum[N][comp.size()-1]+MOD-1)%MOD);
}

Compilation message

boat.cpp: In function 'll comb(ll, ll)':
boat.cpp:28:8: warning: unused variable 'j' [-Wunused-variable]
  ll i, j;
        ^
boat.cpp: In function 'int main()':
boat.cpp:46:12: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(j=0; j<comp.size(); j++) psum[0][j]=1;
           ~^~~~~~~~~~~~
boat.cpp:49:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(j=0; j<comp.size(); j++)
            ~^~~~~~~~~~~~
boat.cpp:66:13: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(j=1; j<comp.size(); j++) psum[i][j]=(dp[i][j]+psum[i][j-1])%MOD;
            ~^~~~~~~~~~~~
boat.cpp:40:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d", &N);
  ~~~~~^~~~~~~~~~
boat.cpp:41:79: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
  for(i=1; i<=N; i++) scanf("%d%d", &A[i], &B[i]), B[i]++, comp.push_back(A[i]), comp.push_back(B[i]);
                      ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 8316 KB Output is correct
2 Correct 28 ms 8312 KB Output is correct
3 Correct 28 ms 8312 KB Output is correct
4 Correct 28 ms 8316 KB Output is correct
5 Correct 28 ms 8312 KB Output is correct
6 Correct 28 ms 8316 KB Output is correct
7 Correct 28 ms 8312 KB Output is correct
8 Correct 28 ms 8312 KB Output is correct
9 Correct 28 ms 8312 KB Output is correct
10 Correct 28 ms 8312 KB Output is correct
11 Correct 28 ms 8284 KB Output is correct
12 Correct 28 ms 8284 KB Output is correct
13 Correct 28 ms 8312 KB Output is correct
14 Correct 28 ms 8312 KB Output is correct
15 Correct 28 ms 8268 KB Output is correct
16 Incorrect 10 ms 5752 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 8316 KB Output is correct
2 Correct 28 ms 8312 KB Output is correct
3 Correct 28 ms 8312 KB Output is correct
4 Correct 28 ms 8316 KB Output is correct
5 Correct 28 ms 8312 KB Output is correct
6 Correct 28 ms 8316 KB Output is correct
7 Correct 28 ms 8312 KB Output is correct
8 Correct 28 ms 8312 KB Output is correct
9 Correct 28 ms 8312 KB Output is correct
10 Correct 28 ms 8312 KB Output is correct
11 Correct 28 ms 8284 KB Output is correct
12 Correct 28 ms 8284 KB Output is correct
13 Correct 28 ms 8312 KB Output is correct
14 Correct 28 ms 8312 KB Output is correct
15 Correct 28 ms 8268 KB Output is correct
16 Incorrect 10 ms 5752 KB Output isn't correct
17 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 48 ms 1400 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 28 ms 8316 KB Output is correct
2 Correct 28 ms 8312 KB Output is correct
3 Correct 28 ms 8312 KB Output is correct
4 Correct 28 ms 8316 KB Output is correct
5 Correct 28 ms 8312 KB Output is correct
6 Correct 28 ms 8316 KB Output is correct
7 Correct 28 ms 8312 KB Output is correct
8 Correct 28 ms 8312 KB Output is correct
9 Correct 28 ms 8312 KB Output is correct
10 Correct 28 ms 8312 KB Output is correct
11 Correct 28 ms 8284 KB Output is correct
12 Correct 28 ms 8284 KB Output is correct
13 Correct 28 ms 8312 KB Output is correct
14 Correct 28 ms 8312 KB Output is correct
15 Correct 28 ms 8268 KB Output is correct
16 Incorrect 10 ms 5752 KB Output isn't correct
17 Halted 0 ms 0 KB -