oj.uz

Submission #313357

# Submission time Handle Problem Language Result Execution time Memory
313357 2020-10-15T21:18:05 Z mohamedsobhi777 Building Bridges (CEOI17_building) C++14
100 / 100
 58 ms 9080 KB 
#include<bits/stdc++.h>


#pragma GCC optimize("-Ofast")
//#pragma GCC optimize("trapv")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,sse4.2,popcnt,abm,mmx,avx2,tune=native")
#pragma GCC optimize("-ffast-math")
#pragma GCC optimize("-funroll-loops")

#define I inline void 
#define S struct 
#define vi vector<int> 
#define vii vector<pair<int,int>>
#define pii pair<int,int>
#define pll pair<ll,ll>

using namespace std ; 
using ll = long long ; 
using ld = long double ; 

const int N = 2e5 + 7 , mod = 1e9 + 7 ; 
const ll inf = 2e18 ; 

// How interesting!

int n ; 
ll ans[N]; 
ll h[N], w[N] ; 
ll pref[N] ; 
vector<pair<ll,ll> > cht ; 

#define MAXLC 1000000000
#define INF (1LL<<60)

inline ll f(ll m, ll b, int x) {
        return m * x + b;
}
ll eval(int l, int r){
        ll diff = h[r] - h[l] ; 
        return 1ll * diff * diff + pref[r - 1] - pref[l] ; 
}

struct lc_node {
        ll m = 0, b = INF;
        lc_node *l = nullptr, *r = nullptr;

        ~lc_node() { delete l; delete r; }

        void add_line(ll nm, ll nb, int lo=0, int hi=MAXLC) {
                int mid = (lo + hi) / 2;
                bool bl = f(nm, nb, lo) < f(m, b, lo);
                bool bm = f(nm, nb, mid) < f(m, b, mid);
                bool bh = f(nm, nb, hi) < f(m, b, hi);
                if (bm) {
                        swap(nm, m);
                        swap(nb, b);
                }
                if (lo == hi || nb == INF)
                        return;
                else if (bl != bm) {
                        if (!l) l = new lc_node;
                        l->add_line(nm, nb, lo, mid - 1);
                }
                else if (bh != bm) {
                        if (!r) r = new lc_node;
                        r->add_line(nm, nb, mid + 1, hi);
                }
        }

        ll get(int x, int lo=0, int hi=MAXLC) {
                int mid = (lo + hi) / 2;
                ll ret = f(m, b, x);
                if (l && x < mid)
                        ret = min(ret, l->get(x, lo, mid - 1));
                if (r && x > mid)
                        ret = min(ret, r->get(x, mid + 1, hi));
                return ret;
        }

        void clear() {
                delete l; delete r;
                m = 0, b = INF, l = nullptr, r = nullptr;
        }

} lc;

int main(){
        ios_base::sync_with_stdio(0) ;
        cin.tie(0) ; 
        //freopen("in.in" , "r" , stdin) ; 
        cin >> n;  

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

        for(int i = 2 ; i <= n; ++ i){
                ll ret = eval(1 , i) ;
                ll cost = 1ll * h[i] * h[i] + pref[i - 1] ; 
                ret = min(ret , lc.get(h[i]) + cost ) ; 
                ans[i] = ret ; 
                lc.add_line( -2ll * h[i] , 1ll * h[i] * h[i] - pref[i] + ans[i] ) ; 
        }
        cout<<ans[n] ; 
        return 0 ; 
}

/*
        - bounds sir (segtree = 4N, eulerTour = 2N, ...)
        - a variable defined twice?
        - will overflow?
        - is it a good complexity?
        - don't mess up indices (0-indexed vs 1-indexed)
        - reset everything between testcases. 
*/

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 1 ms 384 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 58 ms 3704 KB Output is correct
2 Correct 58 ms 4728 KB Output is correct
3 Correct 58 ms 4728 KB Output is correct
4 Correct 55 ms 4472 KB Output is correct
5 Correct 43 ms 6012 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 384 KB Output is correct
2 Correct 0 ms 384 KB Output is correct
3 Correct 0 ms 384 KB Output is correct
4 Correct 1 ms 384 KB Output is correct
5 Correct 1 ms 384 KB Output is correct
6 Correct 58 ms 3704 KB Output is correct
7 Correct 58 ms 4728 KB Output is correct
8 Correct 58 ms 4728 KB Output is correct
9 Correct 55 ms 4472 KB Output is correct
10 Correct 43 ms 6012 KB Output is correct
11 Correct 52 ms 4996 KB Output is correct
12 Correct 50 ms 4856 KB Output is correct
13 Correct 42 ms 4600 KB Output is correct
14 Correct 51 ms 4984 KB Output is correct
15 Correct 50 ms 9080 KB Output is correct
16 Correct 44 ms 6012 KB Output is correct
17 Correct 20 ms 4600 KB Output is correct
18 Correct 20 ms 4608 KB Output is correct