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Submission #1106447

# Submission time Handle Problem Language Result Execution time Memory
1106447 2024-10-30T10:52:43 Z tradz Building Bridges (CEOI17_building) C++14
30 / 100
 115 ms 131072 KB 
#include <bits/stdc++.h>
#define int long long
#define TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define For(i,a,b) for(int i = a; i <= b; i++)
#define Ford(i,a,b) for(int i = a; i >= b; i--)
#define ll long long
#define ii pair<int,int>
#define fi first
#define se second
#define all(v) v.begin(),v.end()
#define RRH(v) v.resize(unique(all(v)) - v.begin())

using namespace std;
const int  N = 1e5+7;
const int M = 1e9+7;
const ll oo = 3e18;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

long long GetRandom(long long l, long long r) {
    return uniform_int_distribution<long long> (l, r)(rng);
}

int n, w[N], h[N];

namespace sub1 {
    int dp[N], pre[N];
    void solve() {
        pre[0] = 0;
        For (i, 1, n) pre[i] = pre[i - 1] + w[i];
        dp[1] = 0;
        For (i, 2, n) {
            dp[i] = oo;
            for (int j = i - 1; j >= 1; j--) {
                dp[i] = min(dp[j] + (h[i] - h[j]) * (h[i] - h[j]) + pre[i - 1] - pre[j], dp[i]);
            }
            //cout << i << " " << dp[i] << '\n';
        }

        cout << dp[n] << '\n';
    }
}

namespace subac {
    int dp[N], pre[N];
struct Line {
    ll a, b;
    Line() {}
    Line(ll a_, ll b_) { a = a_, b = b_; }
    ll operator()(ll x) const {
        return a*x+b;
    }
};

struct seg {
    ll l, r, mid; Line val = Line(0, oo);
    seg() {}
    seg(ll l_, ll r_) { l = l_, r = r_, mid = (l + r) / 2; }
    seg *lc = NULL, *rc = NULL;
    void newNode() {
        if (l + 1 == r || lc != NULL) return;
        lc = new seg(l, mid); rc = new seg(mid, r);
    }
    void add(Line k) {
        if (k(mid) < val(mid)) swap(k, val);
        if (l + 1 == r) return;
        newNode();
        if (k.a > val.a) lc->add(k);
        else rc->add(k);
    }
    ll get(ll x) {
        if (l + 1 == r || lc == NULL) return val(x);
        if (x < mid) return min(val(x), lc->get(x));
        else return min(val(x), rc->get(x));
    }
} T;

    void solve() {
        pre[0] = 0;
        For (i, 1, n) pre[i] = pre[i - 1] + w[i];
        For (i, 1, n) dp[i] = oo;
        dp[1] = 0;
        Line bruh;
        bruh.a = -2ll * h[1];
        bruh.b = 1ll * h[1] * h[1] - pre[1];
        T.add(bruh);
        For (i, 2, n) {
            dp[i] = pre[i - 1] + 1ll * h[i] * h[i] + T.get(h[i]);
            bruh.b = dp[i] - pre[i] + 1ll * h[i] * h[i];
            bruh.a = -2ll * h[i];
            T.add(bruh);
        }
        cout << dp[n] << '\n';
    }
}

int32_t main() {
    ios::sync_with_stdio(0); cin.tie(0);

    #define TASK ""
    if (fopen (".inp", "r")) {
        freopen (".inp", "r", stdin);
        freopen (".out", "w", stdout);
    }
    if(fopen(TASK".inp", "r")) {
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }

    cin >> n;
    For (i, 1, n) cin >> h[i];
    For (i, 1, n) cin >> w[i];

    if (n <= 1000) {
        sub1 :: solve();
        return 0;
    }

    subac :: solve();

    cerr << "Time elapsed: " << TIME << " s.\n";
    return 0;
}

Compilation message

building.cpp: In function 'int32_t main()':
building.cpp:102:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  102 |         freopen (".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~
building.cpp:103:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  103 |         freopen (".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~
building.cpp:106:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  106 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
building.cpp:107:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  107 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4432 KB Output is correct
2 Correct 1 ms 4432 KB Output is correct
3 Correct 1 ms 4432 KB Output is correct
4 Correct 2 ms 4432 KB Output is correct
5 Correct 2 ms 4432 KB Output is correct

Subtask #2
0 / 30.0

# Verdict Execution time Memory Grader output
1 Runtime error 115 ms 131072 KB Execution killed with signal 9
2 Halted 0 ms 0 KB -

Subtask #3
0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 1 ms 4432 KB Output is correct
2 Correct 1 ms 4432 KB Output is correct
3 Correct 1 ms 4432 KB Output is correct
4 Correct 2 ms 4432 KB Output is correct
5 Correct 2 ms 4432 KB Output is correct
6 Runtime error 115 ms 131072 KB Execution killed with signal 9
7 Halted 0 ms 0 KB -