Submission #32233

#	Time	Username	Problem	Language	Result	Execution time	Memory
32233		dqhungdl	Boat (APIO16_boat)	C++14	0 / 100	0 ms	6100 KiB

boat

#include <bits/stdc++.h>
using namespace std;

typedef pair<int,int> ii;
const int mod=1e9+7;
ii Seg[505];
int n,Count=0,res=0,a[505],b[505],f[505],tree[1000005];
map<int,int> mm;

void Sub1()
{
    for(int i=1; i<=n; i++)
    {
        f[i]=1;
        for(int j=1; j<i; j++)
            if(a[j]<a[i])
                f[i]=(f[i]+f[j])%mod;
        res=(res+f[i])%mod;
    }
    cout<<res;
}

void Update(int idx,int data)
{
    while(idx<=Count)
    {
        tree[idx]=(tree[idx]+data)%mod;
        idx+=idx&-idx;
    }
}

int Query(int idx)
{
    int rs=0;
    while(idx>0)
    {
        rs=(rs+tree[idx])%mod;
        idx-=idx&-idx;
    }
    return rs;
}

void Sub2()
{
    for(int i=1; i<=n; i++)
        Seg[i]=ii(a[i],b[i]);
    sort(Seg+1,Seg+n+1);
    for(int i=1; i<=n; i++)
        for(int j=max(Seg[i-1].second,Seg[i].first); j<=Seg[i].second; j++)
            mm[j]=++Count;
    for(int i=1; i<=n; i++)
        for(int j=b[i]; j>=a[i]; j--)
        {
            int jj=mm[j];
            int tmp=Query(jj-1)+1;
            Update(jj,tmp);
            res=(res+tmp)%mod;
        }
    cout<<res;
}

int main()
{
    ios_base::sync_with_stdio(false);
    freopen("BOAT.INP","r",stdin);
    cin>>n;
    int maxn=0;
    bool check=false;
    for(int i=1; i<=n; i++)
    {
        cin>>a[i]>>b[i];
        if(a[i]!=b[i])
            check=true;
        maxn=max(maxn,b[i]-a[i]);
    }
    if(check==false)
        Sub1();
    else if(maxn<=1e6)
        Sub2();
}

Compilation message (stderr)

boat.cpp: In function 'int main()':
boat.cpp:65:34: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
     freopen("BOAT.INP","r",stdin);
                                  ^

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