Submission #656392

#	Time	Username	Problem	Language	Result	Execution time	Memory
656392		HaYoungJoon	Building Bridges (CEOI17_building)	C++14	0 / 100	27 ms	7716 KiB

building

#include <bits/stdc++.h>
#define ll long long

using namespace std;

const ll INF = 1e18;
const int maxV = 1e6 + 1;
int n;

struct line {
    ll A,B;
};

ll getVal(line X, ll y) {
    return X.A*y + X.B;
}

line t[4*maxV];

void update(int v, int tl, int tr, line X) {
    if (tl == tr) {
        if (getVal(X,tl) < getVal(t[v],tl)) t[v] = X;
        return;
    }
    int tm = (tl + tr)/2;
    if (t[v].A < X.A) swap(t[v],X);
    if (getVal(t[v],tm) > getVal(X,tm)) {
        swap(t[v],X);
        update(2*v,tl,tm,X);
    } else {
        update(2*v+1,tm+1,tr,X);
    }
}

ll getMin(int v, int tl, int tr, ll pos) {
    if (tl == tr) return getVal(t[v],pos);
    int tm = (tl + tr)/2;
    return min(getVal(t[v],pos),getMin(2*v,tl,tm,pos));
}

void build(int v, int tl, int tr) {
    if (tl == tr) {
        t[v] = {0,INF};
        return;
    }
    int tm = (tl + tr)/2;
    build(2*v, tl, tm);
    build(2*v+1,tm+1,tr);
    t[v] = {0,INF};
}

const int maxn = 1e5 + 7;
ll dp[maxn];
ll H[maxn], C[maxn];

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0);
    cin >> n;
    ll maxH = 0;
    for (int i = 1; i <= n; i++) {
        cin >> H[i];
        maxH = max(maxH,H[i]);
    }
    for (int i = 1; i <= n; i++) {
        cin >> C[i];
        C[i] += C[i-1];
    }
    build(1,0,maxH);
    line X;
    X.A = H[1];
    X.B = -C[1] + H[1]*H[1];
    update(1,0,maxH,X);
    for (int i = 2; i <= n; i++) {
        dp[i] = getMin(1,0,maxH,-2*H[i]) + H[i]*H[i] + C[i-1];
        X.A = H[i];
        X.B = dp[i] - C[i] + H[i]*H[i];
        update(1,0,maxH,X);
    }
    cout << dp[n];
    return 0;
}

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40