Submission #700888

#	Time	Username	Problem	Language	Result	Execution time	Memory
700888		leeminhduc2	Building Bridges (CEOI17_building)	C++17	100 / 100	119 ms	10756 KiB

building

///leeminhduc2 on his way to TST
#include <bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define ii pair<int,int>
#define sz(x) (int) (x).size()
#define pb push_back
using namespace std;
template<class T1,class T2> bool maximize(T1 &a,T2 b) {return(a<b ? a=b,1:0);};
template<class T1,class T2> bool minimize(T1 &a,T2 b) {return(a>b ? a=b,1:0);};

const int N=1e5+10;
int n,m;
ll h[N],w[N],dp[N];
struct line
{
    ll a,b;
    ll operator()(const ll &x)
    {
        return a*x+b;
    }
};
vector <ll> vec;
line lichao_tree[4*N];

void update(int id,int l,int r,line d)
{

    bool ok1=(d(vec[l])<=lichao_tree[id](vec[l])),ok2=(d(vec[r])<=lichao_tree[id](vec[r]));
    if (ok1&&ok2)
    {
        lichao_tree[id]=d;
    }
    else if (ok1||ok2)
    {
        int mid=(l+r)/2;
        update(id*2,l,mid,d);
        update(id*2+1,mid+1,r,d);
    }
}

ll get(int id,int l,int r,int pos)
{
    if (l==r) return lichao_tree[id](vec[pos]);
    int mid=(l+r)/2;
    if (pos<=mid) return min(lichao_tree[id](vec[pos]),get(id*2,l,mid,pos));
    else return min(lichao_tree[id](vec[pos]),get(id*2+1,mid+1,r,pos));
}

void Lucifer()
{
    cin >> n;
    for (int i=1;i<=n;i++) cin >> h[i];
    for (int i=1;i<=n;i++)
    {
        cin >> w[i];
        w[i]+=w[i-1];
    }

    for (int i=1;i<=n;i++) vec.pb(h[i]);
    sort(vec.begin(),vec.end());
    vec.resize(unique(vec.begin(),vec.end())-vec.begin());
    m=sz(vec);
    for (int i=1;i<=4*m;i++) lichao_tree[i].a=0,lichao_tree[i].b=1e18;
    for (int i=1;i<=n;i++)
    {
        line d;

        if(i==1) dp[i]=0ll;
        else dp[i]=get(1,0,m-1,lower_bound(vec.begin(),vec.end(),h[i])-vec.begin())+h[i]*h[i]+w[i-1];
        d.a=-2ll*h[i];
        d.b=dp[i]-w[i]+h[i]*h[i];
        update(1,0,m-1,d);
    }
    cout << dp[n];

}
signed main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    Lucifer();
}

• Subtask 1: 30 / 30
• Subtask 2: 30 / 30
• Subtask 3: 40 / 40