oj.uz

Submission #1111311

# Submission time Handle Problem Language Result Execution time Memory
1111311 2024-11-12T03:46:42 Z luvna Building Bridges (CEOI17_building) C++14
100 / 100
 45 ms 25672 KB 
#include<bits/stdc++.h>

#define all(v) v.begin(), v.end()
#define compact(v) (v).erase(unique(all(v)), (v).end())
#define endl "\n"

using namespace std;

typedef long long ll;

const int N = 1e6 + 15;

int n, k;
int a[N];
vector<int> compress;

struct line {
    ll a, b;

    line() : a(0), b(0) {}
    line (ll a, ll b) : a(a), b(b) {}

    ll calc (ll x) { return a * x + b; }

    ll slope() { return a; }
};

struct liChao {
    vector<line> tr;

    liChao() {}
    liChao (int sz) : tr(sz + 1, line(0, LLONG_MAX)) {}

    void update (line f, int l, int r) {
        if (l > r) return;
        int mid = (l + r) >> 1;
        if (l == r) {
            tr[mid] = (f.calc(l) < tr[mid].calc(l) ? f : tr[mid]);
            return;
        }
        if (f.calc(mid) < tr[mid].calc(mid)) swap(tr[mid], f);
        if (f.slope() > tr[mid].slope())
            update(f, l, mid - 1);
        if (f.slope() < tr[mid].slope())
            update(f, mid + 1, r);
    }

    ll query (int p, int l, int r) {
        int mid = (l + r) >> 1;
        ll cur = tr[mid].calc(p);
        if (p == mid) return cur;
        if (p < mid) return min(query(p, l, mid - 1), cur);
        if (p > mid) return min(query(p, mid + 1, r), cur);
    }
};

ll dp[N];
ll pref[N];

void solve(){
    cin >> n;

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

    liChao solver(N);

    solver.update(line(-2LL*a[1], 1LL*a[1]*a[1] - pref[1]),0,N);

    for(int i = 2; i <= n; i++){
        dp[i] = 1LL*a[i]*a[i] + pref[i-1] + solver.query(a[i],0,N);
        solver.update(line(-2LL*a[i], 1LL*a[i]*a[i] + dp[i] - pref[i]),0,N);
    }

    cout << dp[n];
}

signed main(){
    ios_base::sync_with_stdio(NULL);
    cin.tie(0); cout.tie(0);

    #define task "task"

    if(fopen(task".INP", "r")){
        freopen(task".INP", "r", stdin);
        freopen(task".OUT", "w", stdout);
    }

    int t; t = 1; //cin >> t;
    while(t--) solve();
}

Compilation message

building.cpp: In member function 'll liChao::query(int, int, int)':
building.cpp:54:5: warning: control reaches end of non-void function [-Wreturn-type]
   54 |     }
      |     ^
building.cpp: In function 'int main()':
building.cpp:85:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |         freopen(task".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
building.cpp:86:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |         freopen(task".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 20048 KB Output is correct
2 Correct 4 ms 20048 KB Output is correct
3 Correct 4 ms 20060 KB Output is correct
4 Correct 4 ms 20048 KB Output is correct
5 Correct 4 ms 20216 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 37 ms 25048 KB Output is correct
2 Correct 37 ms 25424 KB Output is correct
3 Correct 36 ms 25260 KB Output is correct
4 Correct 39 ms 25416 KB Output is correct
5 Correct 37 ms 25424 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 4 ms 20048 KB Output is correct
2 Correct 4 ms 20048 KB Output is correct
3 Correct 4 ms 20060 KB Output is correct
4 Correct 4 ms 20048 KB Output is correct
5 Correct 4 ms 20216 KB Output is correct
6 Correct 37 ms 25048 KB Output is correct
7 Correct 37 ms 25424 KB Output is correct
8 Correct 36 ms 25260 KB Output is correct
9 Correct 39 ms 25416 KB Output is correct
10 Correct 37 ms 25424 KB Output is correct
11 Correct 45 ms 25672 KB Output is correct
12 Correct 44 ms 25248 KB Output is correct
13 Correct 37 ms 25408 KB Output is correct
14 Correct 43 ms 25416 KB Output is correct
15 Correct 34 ms 25160 KB Output is correct
16 Correct 38 ms 25416 KB Output is correct
17 Correct 20 ms 25312 KB Output is correct
18 Correct 19 ms 25436 KB Output is correct