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Submission #824106

# Submission time Handle Problem Language Result Execution time Memory
824106 2023-08-13T14:05:20 Z ttamx Building Bridges (CEOI17_building) C++14
100 / 100
 41 ms 9736 KB 
#include<bits/stdc++.h>

using namespace std;

typedef long long ll;

const int N=1e5+5;
const ll inf=1e18;

int n;
ll h[N],w[N],qs[N],dp;

bool querymode=false;

struct line{
    ll m,c;
    mutable ll p;
    line(ll m,ll c):m(m),c(c),p(0){}
    line(ll p):m(0),c(0),p(p){}
    bool operator<(const line &o)const{
        return querymode?p<o.p:m>o.m;
    }
};

struct convexhulltrick:multiset<line>{
    ll div(ll a,ll b){
        return a/b-((a^b)<0&&a%b);
    }
    bool isect(iterator x,iterator y){
        if(y==end())return x->p=inf,false;
        if(x->m==y->m)x->p=x->c<=y->c?inf:-inf;
        else x->p=div(x->c-y->c,y->m-x->m);
        return x->p>=y->p;
    }
    void add(ll m,ll c){
        auto x=insert(line(m,c)),y=next(x);
        while(isect(x,y))y=erase(y);
        if((y=x)!=begin()&&isect(--x,y))isect(x,erase(y));
        while((y=x)!=begin()&&(--x)->p>=y->p)isect(x,erase(y));
    }
    ll get(ll x){
        if(empty())return inf;
        querymode=true;
        auto l=lower_bound(line(x));
        querymode=false;
        return l->m*x+l->c;
    }
}cht;

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    cin >> n;
    for(int i=1;i<=n;i++)cin >> h[i];
    for(int i=1;i<=n;i++)cin >> w[i];
    for(int i=1;i<=n;i++)qs[i]=qs[i-1]+w[i];
    cht.add(-2*h[1],-qs[1]+h[1]*h[1]);
    for(int i=2;i<=n;i++){
        dp=h[i]*h[i]+qs[i-1]+cht.get(h[i]);
        cht.add(-2*h[i],dp-qs[i]+h[i]*h[i]);
    }
    cout << dp;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 31 ms 2672 KB Output is correct
2 Correct 38 ms 3652 KB Output is correct
3 Correct 36 ms 3708 KB Output is correct
4 Correct 29 ms 3516 KB Output is correct
5 Correct 28 ms 4768 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 1 ms 340 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 31 ms 2672 KB Output is correct
7 Correct 38 ms 3652 KB Output is correct
8 Correct 36 ms 3708 KB Output is correct
9 Correct 29 ms 3516 KB Output is correct
10 Correct 28 ms 4768 KB Output is correct
11 Correct 30 ms 3844 KB Output is correct
12 Correct 32 ms 3664 KB Output is correct
13 Correct 25 ms 3764 KB Output is correct
14 Correct 32 ms 3884 KB Output is correct
15 Correct 41 ms 9736 KB Output is correct
16 Correct 28 ms 4684 KB Output is correct
17 Correct 20 ms 3796 KB Output is correct
18 Correct 17 ms 3664 KB Output is correct