oj.uz

Submission #907047

# Submission time Handle Problem Language Result Execution time Memory
907047 2024-01-15T06:22:23 Z ibm2006 Tents (JOI18_tents) C++17
100 / 100
 130 ms 160988 KB 
#include<bits/stdc++.h>
using namespace std;
typedef long long int ll;
const ll mod=1000000007;
ll n,i,j,k,l,r,x,y,z,w,s,t,two[11000],four[11000],invtwo[11000],fac[11000],invfac[11000],m,dp[3300][3300],b[3300][3300];
ll inv(ll x)
{
    ll y=mod-2,s=1;
    while(y)
    {
        if(y&1)
        {
            s=s*x%mod;
        }

        x=x*x%mod;
        y>>=1;
    }
    return s;
}
ll C(ll x,ll y)
{
    if(x<0)
        return 0;
    if(y<0||y>x)
        return 0;
    return fac[x]*invfac[y]%mod*invfac[x-y]%mod;
}
ll g(ll n,ll m)
{
    ll i,j,s=0;
    if(n<0||m<0)
        return 0;
    if(n==0||m==0)
        return 1;
    for(i=0;i<=m&&n-i*2>=0;i++)
    {
        s=(s+C(m,i)*C(n,2*i)%mod*fac[i*2]%mod*invtwo[i]%mod*dp[n-2*i][m-i]%mod)%mod;
    }
    return s;
}
ll f(ll n,ll m)
{
    ll i,j,s=0;
    if(n>m)
        swap(n,m);
    for(i=0;i<=n;i++)
    {
        s=(s+C(n,i)*C(m,2*i)%mod*fac[i*2]%mod*invtwo[i]%mod*g(n-i,m-2*i))%mod;
    }
    return s;
}
int main()
{
    for(i=0;i<=3000;i++)
    {
        dp[i][0]=1;
        dp[0][i]=1;
        b[0][i]=1;
        b[i][0]=i+1;
    }
    for(i=1;i<=3000;i++)
    {
        for(j=1;j<=3000;j++)
        {
            dp[i][j]=1+(b[i-1][j-1])*4%mod*j%mod;
            dp[i][j]%=mod;
            b[i][j]=(b[i-1][j]+dp[i][j])%mod;
        }
    }
    scanf("%lld %lld",&n,&m);
    fac[0]=1;
    invfac[0]=1;
    for(i=1;i<=10000;i++)
    {
        fac[i]=fac[i-1]*i%mod;
        invfac[i]=inv(fac[i]);
    }
    two[0]=1;
    invtwo[0]=1;
    for(i=1;i<=10000;i++)
    {
        two[i]=two[i-1]*2%mod;
        invtwo[i]=inv(two[i]);
    }
    four[0]=1;
    for(i=1;i<=10000;i++)
    {
        four[i]=four[i-1]*4%mod;
    }
    s=f(n,m);
    s=(s+mod-1)%mod;
    printf("%lld",s);
}

Compilation message

tents.cpp: In function 'll g(ll, ll)':
tents.cpp:31:10: warning: unused variable 'j' [-Wunused-variable]
   31 |     ll i,j,s=0;
      |          ^
tents.cpp: In function 'll f(ll, ll)':
tents.cpp:44:10: warning: unused variable 'j' [-Wunused-variable]
   44 |     ll i,j,s=0;
      |          ^
tents.cpp: In function 'int main()':
tents.cpp:71:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   71 |     scanf("%lld %lld",&n,&m);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~

Subtask #1
48.0 / 48.0

# Verdict Execution time Memory Grader output
1 Correct 83 ms 160852 KB Output is correct
2 Correct 84 ms 160920 KB Output is correct
3 Correct 104 ms 160900 KB Output is correct
4 Correct 92 ms 160900 KB Output is correct
5 Correct 84 ms 160904 KB Output is correct
6 Correct 103 ms 160900 KB Output is correct
7 Correct 96 ms 160904 KB Output is correct
8 Correct 93 ms 160964 KB Output is correct
9 Correct 83 ms 160908 KB Output is correct
10 Correct 83 ms 160904 KB Output is correct
11 Correct 94 ms 160908 KB Output is correct
12 Correct 102 ms 160852 KB Output is correct

Subtask #2
52.0 / 52.0

# Verdict Execution time Memory Grader output
1 Correct 83 ms 160852 KB Output is correct
2 Correct 84 ms 160920 KB Output is correct
3 Correct 104 ms 160900 KB Output is correct
4 Correct 92 ms 160900 KB Output is correct
5 Correct 84 ms 160904 KB Output is correct
6 Correct 103 ms 160900 KB Output is correct
7 Correct 96 ms 160904 KB Output is correct
8 Correct 93 ms 160964 KB Output is correct
9 Correct 83 ms 160908 KB Output is correct
10 Correct 83 ms 160904 KB Output is correct
11 Correct 94 ms 160908 KB Output is correct
12 Correct 102 ms 160852 KB Output is correct
13 Correct 85 ms 160904 KB Output is correct
14 Correct 87 ms 160988 KB Output is correct
15 Correct 104 ms 160904 KB Output is correct
16 Correct 114 ms 160904 KB Output is correct
17 Correct 90 ms 160852 KB Output is correct
18 Correct 114 ms 160900 KB Output is correct
19 Correct 109 ms 160848 KB Output is correct
20 Correct 107 ms 160856 KB Output is correct
21 Correct 105 ms 160852 KB Output is correct
22 Correct 98 ms 160836 KB Output is correct
23 Correct 89 ms 160916 KB Output is correct
24 Correct 130 ms 160908 KB Output is correct
25 Correct 114 ms 160916 KB Output is correct
26 Correct 114 ms 160904 KB Output is correct
27 Correct 124 ms 160912 KB Output is correct