oj.uz

Submission #417525

# Submission time Handle Problem Language Result Execution time Memory
417525 2021-06-03T21:09:39 Z JerryLiu06 Building Bridges (CEOI17_building) C++17
100 / 100
 84 ms 66504 KB 
#include <bits/stdc++.h>
 
using namespace std;
 
using ll = long long;
using ld = long double;
using db = double;
using str = string;
 
using pi = pair<int, int>;
using pl = pair<ll, ll>;
using pd = pair<db, db>;
 
using vi = vector<int>;
using vb = vector<bool>;
using vl = vector<ll>;
using vd = vector<db>;
using vs = vector<str>;
using vpi = vector<pi>;
using vpl = vector<pl>;
using vpd = vector<pd>;
 
#define mp make_pair
#define f first
#define s second
 
#define sz(x) (int)(x).size()
#define bg(x) begin(x)
#define all(x) bg(x), end(x)
#define sor(x) sort(all(x))
#define ft front()
#define bk back()
#define pb push_back
#define pf push_front
 
#define lb lower_bound
#define ub upper_bound
 
#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define EACH(a,x) for (auto& a: x)
 
const int MOD = 1e9 + 7;
const int MX = 1e6 + 10; 
const ll INF = 1e18; 

// Description: Li Chao Segment Tree. You can add lines of the form kx + m, and query maximum
// values at points x. *Useful for dynamic programming (CHT)* Time: O(lg N)

struct Line {
    ll M, C; Line() { M = 0, C = INF; } Line(ll _M, ll _C) { M = _M; C = _C; }

    ll operator()(ll X) { return M * X + C; }
};

struct LiChaoSegTree {
    Line tree[4 * MX];

    void update(int x, int l, int r, Line line) { int mid = (l + r) / 2;
        bool L = tree[x](l) > line(l); bool M = tree[x](mid) > line(mid); bool R = tree[x](r) > line(r);

        if (L == R) { if (L) swap(line, tree[x]); return ; }

        if (L == M) { if (L) swap(tree[x], line); update(2 * x + 1, mid + 1, r, line); }
        if (M == R) { if (R) swap(tree[x], line); update(2 * x, l, mid, line); }
    }
    ll query(int x, int l, int r, int pos) { int mid = (l + r) / 2;
        if (l == r) return tree[x](pos);
        
        if (pos <= mid) return min(tree[x](pos), query(2 * x, l, mid, pos));
        
        if (pos > mid) return min(tree[x](pos), query(2 * x + 1, mid + 1, r, pos));

        //return min(query(2 * x, l, mid, pos), query(2 * x + 1, mid + 1, r, pos));
    }
};
int N; ll H[MX], W[MX], tot; ll DP[MX]; LiChaoSegTree LC;

int main() {
    ios_base::sync_with_stdio(false); cin.tie(0);

    ios_base::sync_with_stdio(false); cin.tie(0);

    cin >> N; FOR(i, 1, N + 1) cin >> H[i]; FOR(i, 1, N + 1) cin >> W[i], tot += W[i];

    DP[1] = -W[1]; FOR(i, 2, N + 1) {
        Line cur = Line(-2 * H[i - 1], DP[i - 1] + H[i - 1] * H[i - 1]); LC.update(1, 0, 1e6, cur);

        DP[i] = LC.query(1, 0, 1e6, H[i]) - W[i] + H[i] * H[i];
    }
    cout << tot + DP[N];
}

Compilation message

building.cpp: In member function 'll LiChaoSegTree::query(int, int, int, int)':
building.cpp:77:5: warning: control reaches end of non-void function [-Wreturn-type]
   77 |     }
      |     ^

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 62916 KB Output is correct
2 Correct 28 ms 62880 KB Output is correct
3 Correct 29 ms 62916 KB Output is correct
4 Correct 28 ms 62916 KB Output is correct
5 Correct 33 ms 62984 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 75 ms 66220 KB Output is correct
2 Correct 77 ms 66192 KB Output is correct
3 Correct 83 ms 66244 KB Output is correct
4 Correct 74 ms 66176 KB Output is correct
5 Correct 66 ms 66172 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 32 ms 62916 KB Output is correct
2 Correct 28 ms 62880 KB Output is correct
3 Correct 29 ms 62916 KB Output is correct
4 Correct 28 ms 62916 KB Output is correct
5 Correct 33 ms 62984 KB Output is correct
6 Correct 75 ms 66220 KB Output is correct
7 Correct 77 ms 66192 KB Output is correct
8 Correct 83 ms 66244 KB Output is correct
9 Correct 74 ms 66176 KB Output is correct
10 Correct 66 ms 66172 KB Output is correct
11 Correct 84 ms 66464 KB Output is correct
12 Correct 82 ms 66172 KB Output is correct
13 Correct 67 ms 66504 KB Output is correct
14 Correct 83 ms 66372 KB Output is correct
15 Correct 70 ms 66148 KB Output is correct
16 Correct 67 ms 66212 KB Output is correct
17 Correct 55 ms 66244 KB Output is correct
18 Correct 54 ms 66244 KB Output is correct