Submission #1067028

#	Time	Username	Problem	Language	Result	Execution time	Memory
1067028		steveonalex	Building Bridges (CEOI17_building)	C++17	100 / 100	104 ms	65876 KiB

building

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
#define block_of_code if(true)
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
ll gcd(ll a, ll b){return __gcd(a, b);}
ll lcm(ll a, ll b){return a / gcd(a, b) * b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ull mask){return __builtin_ctzll(mask);}
int logOf(ull mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
double rngesus_d(double l, double r){
    double cur = rngesus(0, MASK(60) - 1);
    cur /= MASK(60) - 1;
    return l + cur * (r - l);
}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }


const ll INF = 1e18 + 69;

struct SegmentTree{
    int n;
    vector<pair<int, ll>> a;

    SegmentTree(int _n){
        n = _n;
        a.resize(n * 4 + 4, {0, INF});
    }

    ll sqr(ll a){return a * a;}

    ll f(int x, pair<int, ll> sigma){
        return sqr(sigma.first - x) + sigma.second;
    }

    ll get(int i){
        int id = 1, l = 0, r = n;
        ll ans = INF;
        while(l < r){
            minimize(ans, f(i, a[id]));
            int mid = (l + r) >> 1;
            if (i <= mid) {
                r = mid;
                id = id * 2;
            }
            else{
                l = mid + 1;
                id = id * 2 + 1;
            }
        }
        minimize(ans, f(i, a[id]));
        return ans;
    }

    void update(int u, int v, pair<int, ll> slope, int l, int r, int id){
        int mid = (l + r) >> 1;
        if (u <= l && r <= v){
            if (f(l, slope) >= f(l, a[id]) && f(r,slope) >= f(r, a[id])) return;
            if (f(l, slope) <= f(l, a[id]) && f(r,slope) <= f(r, a[id])) {
                a[id] = slope;
                return;
            }
            else{
                update(u, v, slope, l, mid, id * 2);
                update(u, v, slope, mid + 1, r, id * 2 + 1);
            }
            return;
        }
        if (u <= mid) update(u, v, slope, l, mid, id * 2);
        if (v > mid) update(u, v, slope, mid + 1, r, id * 2 + 1);
    }

    void update(int u, int v, pair<int, ll> slope){
        update(u, v, slope, 0, n, 1);
    }
};

int main(void){
    ios::sync_with_stdio(0);cin.tie(0); cout.tie(0);
    clock_t start = clock();

    int n; cin >> n;
    vector<int> a(n+1), w(n+1);
    for(int i = 1; i<=n; ++i) cin >> a[i];
    for(int i = 1; i<=n; ++i) cin >> w[i];

    ll sum = 0;
    for(int i: w) sum += i;

    SegmentTree st(1e6); st.update(0, 1e6, {a[1], -w[1]});
    vector<ll> dp(n+1); dp[1] = w[1];
    for(int i = 2; i<=n; ++i){
        dp[i] = st.get(a[i]) - w[i];
        st.update(0, i, {a[i], dp[i]});
        st.update(i, 1e6, {a[i], dp[i]});
    }
    cout << dp[n] + sum << "\n";

    cerr << "Time elapsed: " << clock() - start << " ms\n";
    return 0;
}

// ac#aa

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