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Submission #113428

# Submission time Handle Problem Language Result Execution time Memory
113428 2019-05-25T14:52:06 Z ansol4328 Boat (APIO16_boat) C++11
9 / 100
 448 ms 8420 KB 
#include<stdio.h>
#include<algorithm>
#include<map>

using namespace std;
typedef long long ll;

ll n, m[505][2];
ll v[1005], inv[505];
ll dp1[505][1005], dp2[505][1005];
map<ll,ll> cont;
const ll MOD=1e9+7;

ll get_mod(ll x, ll y)
{
    if(y==1) return x;
    ll ret=get_mod(x,y/2);
    (ret*=ret)%=MOD;
    if(y%2==1) (ret*=x)%=MOD;
    return ret;
}

int main()
{
    scanf("%lld",&n);
    inv[n]=1;
    for(ll i=1 ; i<=n ; i++)
    {
        scanf("%lld %lld",&m[i][0],&m[i][1]);
        cont[m[i][0]]=0;
        cont[m[i][1]]=0;
        (inv[n]*=i)%=MOD;
    }
    //contracting
    ll cnt=0, contn;
    for(auto it=cont.begin() ; it!=cont.end() ; it++)
    {
        it->second=++cnt;
        v[cnt]=it->first;
    }
    contn=cnt;
    for(ll i=1 ; i<=n ; i++)
    {
        m[i][0]=cont[m[i][0]];
        m[i][1]=cont[m[i][1]];
    }
    //making modular inverse
    inv[n]=get_mod(inv[n],MOD-2);
    for(ll i=n ; i>1 ; i--) inv[i-1]=(inv[i]*i)%MOD;

    //DP
    ll res=0;
    for(ll i=0 ; i<=contn ; i++) dp1[0][i]=1;
    for(ll i=1 ; i<=n ; i++)
    {
        for(ll j=m[i][0] ; j<m[i][1] ; j++)
        {
            ll gap=v[j+1]-v[j];
            ll k1=gap-1, fac1=gap, c=1;
            for(ll k=i-1 ; k>=0 ; k--) (dp1[i][j]+=(dp1[k][j-1]*gap))%=MOD;
            for(ll k=i-1 ; k>=1 ; k--)
            {
                if(k1<=0) break;
                if(m[k][0]<=j && j+1<=m[k][1])
                {
                    c++;
                    (fac1*=k1)%=MOD;
                    ll val=(dp1[k-1][j-1]*fac1)%MOD;
                    (val*=inv[c])%=MOD;
                    (dp1[i][j]+=val)%=MOD;
                    k1--;
                }
            }
        }
        for(ll j=i-1 ; j>=0 ; j--) (dp2[i][m[i][1]]+=dp1[j][m[i][1]-1])%=MOD;
        for(ll j=1 ; j<=contn ; j++)
        {
            (dp1[i][j]+=dp1[i][j-1]+dp2[i][j])%=MOD;
            (dp2[i][j]+=dp2[i][j-1])%=MOD;
        }
        (res+=dp1[i][contn])%=MOD;
    }
    printf("%lld",res);
    return 0;
}

Compilation message

boat.cpp: In function 'int main()':
boat.cpp:25:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%lld",&n);
     ~~~~~^~~~~~~~~~~
boat.cpp:29:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
         scanf("%lld %lld",&m[i][0],&m[i][1]);
         ~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
9.0 / 9.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 8320 KB Output is correct
2 Correct 12 ms 8192 KB Output is correct
3 Correct 12 ms 8192 KB Output is correct
4 Correct 12 ms 8320 KB Output is correct
5 Correct 12 ms 8320 KB Output is correct
6 Correct 13 ms 8320 KB Output is correct
7 Correct 14 ms 8320 KB Output is correct
8 Correct 15 ms 8192 KB Output is correct
9 Correct 13 ms 8320 KB Output is correct
10 Correct 14 ms 8320 KB Output is correct
11 Correct 13 ms 8192 KB Output is correct
12 Correct 13 ms 8192 KB Output is correct
13 Correct 20 ms 8192 KB Output is correct
14 Correct 13 ms 8320 KB Output is correct
15 Correct 13 ms 8320 KB Output is correct
16 Correct 8 ms 4992 KB Output is correct
17 Correct 7 ms 5120 KB Output is correct
18 Correct 7 ms 5120 KB Output is correct
19 Correct 8 ms 5120 KB Output is correct
20 Correct 7 ms 4992 KB Output is correct

Subtask #2
0 / 22.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 8320 KB Output is correct
2 Correct 12 ms 8192 KB Output is correct
3 Correct 12 ms 8192 KB Output is correct
4 Correct 12 ms 8320 KB Output is correct
5 Correct 12 ms 8320 KB Output is correct
6 Correct 13 ms 8320 KB Output is correct
7 Correct 14 ms 8320 KB Output is correct
8 Correct 15 ms 8192 KB Output is correct
9 Correct 13 ms 8320 KB Output is correct
10 Correct 14 ms 8320 KB Output is correct
11 Correct 13 ms 8192 KB Output is correct
12 Correct 13 ms 8192 KB Output is correct
13 Correct 20 ms 8192 KB Output is correct
14 Correct 13 ms 8320 KB Output is correct
15 Correct 13 ms 8320 KB Output is correct
16 Correct 8 ms 4992 KB Output is correct
17 Correct 7 ms 5120 KB Output is correct
18 Correct 7 ms 5120 KB Output is correct
19 Correct 8 ms 5120 KB Output is correct
20 Correct 7 ms 4992 KB Output is correct
21 Incorrect 448 ms 8420 KB Output isn't correct
22 Halted 0 ms 0 KB -

Subtask #3
0 / 27.0

# Verdict Execution time Memory Grader output
1 Incorrect 17 ms 1408 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 42.0

# Verdict Execution time Memory Grader output
1 Correct 12 ms 8320 KB Output is correct
2 Correct 12 ms 8192 KB Output is correct
3 Correct 12 ms 8192 KB Output is correct
4 Correct 12 ms 8320 KB Output is correct
5 Correct 12 ms 8320 KB Output is correct
6 Correct 13 ms 8320 KB Output is correct
7 Correct 14 ms 8320 KB Output is correct
8 Correct 15 ms 8192 KB Output is correct
9 Correct 13 ms 8320 KB Output is correct
10 Correct 14 ms 8320 KB Output is correct
11 Correct 13 ms 8192 KB Output is correct
12 Correct 13 ms 8192 KB Output is correct
13 Correct 20 ms 8192 KB Output is correct
14 Correct 13 ms 8320 KB Output is correct
15 Correct 13 ms 8320 KB Output is correct
16 Correct 8 ms 4992 KB Output is correct
17 Correct 7 ms 5120 KB Output is correct
18 Correct 7 ms 5120 KB Output is correct
19 Correct 8 ms 5120 KB Output is correct
20 Correct 7 ms 4992 KB Output is correct
21 Incorrect 448 ms 8420 KB Output isn't correct
22 Halted 0 ms 0 KB -