Submission #403989

#	Time	Username	Problem	Language	Result	Execution time	Memory
403989		sad	Boat (APIO16_boat)	C++14	9 / 100	2081 ms	311280 KiB

boat

#include <bits/stdc++.h>
#define ll long long
#define fi first
#define se second
#define pb push_back
using namespace std;
int dp[2][2000090],a[503],b[503];
int n;
const int mod=1e9+7;
vector<int>v;
set<int>s;
int main()
{ios::sync_with_stdio(0);cin.tie(0);cout.tie(0);
    cin>>n;v.pb(0);
    for(int i=1; i<=n; i++)
    {
        cin>>a[i]>>b[i];
        for(int j=a[i]; j<=b[i]; j++)
        {
            s.insert(j);
        }
    }
    while(s.size()>0)
    {
        v.pb(*s.begin());
        s.erase(s.begin());
    }int m=v.size();
    for(int i=0;i<m;i++)dp[0][i]=1;
    dp[1][0]=1;
    for(int i=1;i<n+1;i++)
    {int g=i%2;
            int gg=(i+1)%2;
        for(int j=1; j<m; j++)
        {int u=0;
            u+=dp[gg][j];
            u%=mod;int x=i,y=j;
            if(a[i]<=v[j]&&b[i]>=v[j])
            {
                u+=dp[gg][y-1];
                u%=mod;
                u+=dp[g][y-1];
                u%=mod;
                u-=dp[gg][y-1];
                u+=mod;
                u%=mod;
            }
            else
            {
                u+=dp[g][y-1];
                u%=mod;
                u-=dp[gg][y-1];
                u+=mod;
                u%=mod;
            }
        dp[g][j]=u;u=0;
        }
        for(int j=0;j<m+1;j++)dp[gg][j]=0;
        dp[gg][0]=1;
    }
    int w=n%2;
    cout<<dp[w][m-1]-1;
}

Compilation message (stderr)

boat.cpp: In function 'int main()':
boat.cpp:36:24: warning: unused variable 'x' [-Wunused-variable]
   36 |             u%=mod;int x=i,y=j;
      |                        ^

• Subtask 1: 9 / 9
• Subtask 2: 0 / 22
• Subtask 3: 0 / 27
• Subtask 4: 0 / 42