oj.uz

Submission #597586

# Submission time Handle Problem Language Result Execution time Memory
597586 2022-07-16T10:54:33 Z OttoTheDino Building Bridges (CEOI17_building) C++17
100 / 100
 103 ms 16872 KB 
#include <bits/stdc++.h>
using namespace std;

#define rep(i,s,e)                  for (int i = s; i <= e; ++i)
#define rrep(i,s,e)                 for (int i = s; i >= e; --i)
#define pb                          push_back
#define pf                          push_front
#define fi                          first
#define se                          second
#define all(a)                      a.begin(), a.end()
#define len(a)                      (int)a.size()
typedef long long ll;
typedef pair<int, int> ii;
typedef pair<ll, ll> pll;
typedef vector<ii> vii;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<string> vs;
typedef vector<ll> vll;

//let's implement cht then :)))))))))

const ll inf = 1e9;

ll cdiv (ll a, ll b) {
    return  a / b + !(((a < 0) != (b < 0)) || !(a % b));
}

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

    ll n, s = 0;
    cin >> n;
    ll h[n+1], w[n+1], x[n+1], dp[n+1];

    set<pll,greater<pll>> stk;
    set<pll> stx;

    rep (i,1,n) cin >> h[i];
    rep (i,1,n) {
        cin >> w[i];
        s += w[i];
    }

    dp[1] = h[1]*h[1] - w[1];
    stk.insert({-2*h[1],1});  
    stx.insert({-inf,1});  
    x[1] = -inf;

    rep (i,2,n) {
        auto iti = stx.upper_bound({h[i], inf});
        --iti;

        ll u = (*iti).se;

        dp[i] = dp[u] + -2*h[u]*h[i] + h[i] * h[i] - w[i];

        if (i==n) cout << s+dp[n] << "\n";

        else {
            //add an element to the cht
            dp[i] += h[i]*h[i];

            auto it = stk.upper_bound({-2*h[i], -inf});
            
            bool beg = 0;
            if (it!=stk.begin()) {
                --it;
                while (true) {
                    if ((*it).fi==-2*h[i]) {
                        if (dp[i] >= dp[(*it).se]) break;
                    }
                    else {
                        ll nx = cdiv(dp[(*it).se]-dp[i],-2*h[i]-(*it).fi);
                        if (nx>x[(*it).se]) break;
                    }
                    stx.erase({x[(*it).se], (*it).se});
                    it = stk.erase(it);
                    if (it==stk.begin()) {
                        beg = 1;
                        break;
                    }
                    --it;
                }
            }
            else beg = 1;

            if (beg) {
                stk.insert({-2*h[i], i});
                x[i] = -inf;
                stx.insert({-inf, i});
            }
            else {
                if ((*it).fi==-2*h[i]) continue;
                int X = cdiv(dp[(*it).se]-dp[i],-2*h[i]-(*it).fi); 
                ++it;
                if (it==stk.end() || X <= x[(*it).se]) {
                    if (it!=stk.end() && X==x[(*it).se]) {
                       if (cdiv(dp[(*it).se]-dp[i],-2*h[i]-(*it).fi)<=X) continue;
                    }
                    stx.insert({X, i});
                    stk.insert({-2*h[i],i});
                    x[i] = X;
                }
                else continue;
            }

            while (true) {
                if (it==stk.end()) break;

                int X = cdiv(dp[(*it).se]-dp[i],-2*h[i]-(*it).fi); 
                ++it;

                if (it==stk.end()) {
                    --it;
                    stx.erase({x[(*it).se], (*it).se});
                    stx.insert({X, (*it).se});
                    x[(*it).se] = X;
                    break;
                }

                if (X >= x[(*it).se]) {
                    --it;
                    stx.erase({x[(*it).se], (*it).se}); 
                    it = stk.erase(it);
                }

                else {
                    --it;
                    stx.erase({x[(*it).se], (*it).se});
                    stx.insert({X, (*it).se});
                    x[(*it).se] = X;
                    break;
                }
            }
        }
    }


    return 0;
}

Subtask #1
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct

Subtask #2
30.0 / 30.0

# Verdict Execution time Memory Grader output
1 Correct 90 ms 4548 KB Output is correct
2 Correct 92 ms 4692 KB Output is correct
3 Correct 90 ms 4520 KB Output is correct
4 Correct 89 ms 4400 KB Output is correct
5 Correct 95 ms 6740 KB Output is correct

Subtask #3
40.0 / 40.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 90 ms 4548 KB Output is correct
7 Correct 92 ms 4692 KB Output is correct
8 Correct 90 ms 4520 KB Output is correct
9 Correct 89 ms 4400 KB Output is correct
10 Correct 95 ms 6740 KB Output is correct
11 Correct 79 ms 4676 KB Output is correct
12 Correct 93 ms 4576 KB Output is correct
13 Correct 51 ms 4548 KB Output is correct
14 Correct 103 ms 4704 KB Output is correct
15 Correct 97 ms 16872 KB Output is correct
16 Correct 95 ms 6744 KB Output is correct
17 Correct 16 ms 4436 KB Output is correct
18 Correct 15 ms 4460 KB Output is correct