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Submission #817573

# Submission time Handle Problem Language Result Execution time Memory
817573 2023-08-09T13:39:41 Z 12345678 Building Bridges (CEOI17_building) C++17
100 / 100
 45 ms 8928 KB 
#include <bits/stdc++.h>

using namespace std;

#define ll long long

const ll nx=1e5+5, inf=1e18;
ll n, h[nx], w[nx], sm;
bool querymode;

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

struct convexhull:multiset<line>
{
    ll div(ll a, ll b)
    {
        if (a%b==0||(a^b)>=0) return a/b;
        return a/b-1;
    }
    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, 0)), y=next(x);
        while (isect(x, y)) y=erase(next(x));
        if ((y=x)!=begin()&&isect(--x, y)) isect(x, erase(y));
        while ((y=x)!=begin()&&(--x)->p>=y->p) isect(x, erase(y));
    }
    ll query(ll x)
    {
        if (empty()) return inf;
        querymode=1;
        auto l=lower_bound(line(0, 0, x));
        querymode=0;
        return l->m*x+l->c;
    }
} c;

int main()
{
    cin.tie(NULL)->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], sm+=w[i];
    c.add(-2*h[1], h[1]*h[1]-w[1]);
    for (int i=2; i<=n-1; i++)
    {
        ll tmp=c.query(h[i])+h[i]*h[i]-w[i];
        c.add(-2*h[i], tmp+h[i]*h[i]);
    }
    cout<<c.query(h[n])+h[n]*h[n]-w[n]+sm;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 1 ms 344 KB Output is correct
5 Correct 1 ms 336 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 35 ms 2956 KB Output is correct
2 Correct 36 ms 2956 KB Output is correct
3 Correct 37 ms 2928 KB Output is correct
4 Correct 29 ms 2772 KB Output is correct
5 Correct 30 ms 3944 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 340 KB Output is correct
2 Correct 0 ms 340 KB Output is correct
3 Correct 0 ms 340 KB Output is correct
4 Correct 1 ms 344 KB Output is correct
5 Correct 1 ms 336 KB Output is correct
6 Correct 35 ms 2956 KB Output is correct
7 Correct 36 ms 2956 KB Output is correct
8 Correct 37 ms 2928 KB Output is correct
9 Correct 29 ms 2772 KB Output is correct
10 Correct 30 ms 3944 KB Output is correct
11 Correct 35 ms 3072 KB Output is correct
12 Correct 34 ms 2944 KB Output is correct
13 Correct 28 ms 2992 KB Output is correct
14 Correct 36 ms 3120 KB Output is correct
15 Correct 45 ms 8928 KB Output is correct
16 Correct 40 ms 3976 KB Output is correct
17 Correct 18 ms 2928 KB Output is correct
18 Correct 18 ms 2944 KB Output is correct