Submission #675027

#	Time	Username	Problem	Language	Result	Execution time	Memory
675027		Danilo21	Aliens (IOI16_aliens)	C++17	60 / 100	1865 ms	246184 KiB

aliens

#include <bits/stdc++.h>
#include "aliens.h"

#define ll long long
#define ld long double
#define pb push_back
#define fi first
#define se second
#define en '\n'
#define sp ' '
#define tb '\t'
#define ri(n) int n; cin >> n
#define rl(n) ll n; cin >> n
#define rs(s) string s; cin >> s
#define rc(c) char c; cin >> c
#define rv(v) for (auto &x : v) cin >> x
#define pven(v) for (auto x : v) cout << x << en
#define pv(v) for (auto x : v) cout << x << sp; cout << en
#define all(v) v.begin(), v.end()
#define rall(v) v.rbegin(), v.rend()
#define yes cout << "YES" << en
#define no cout << "NO" << en
#define smin(a, b) a = min(a, b)
#define smax(a, b) a = max(a, b)
#define ssort(a, b) if (a < b) swap(a, b)
#define bitcnt(a) (__builtin_popcountll(a))
#define bithigh(a) (63-__builtin_clzll(a))
#define lg bithigh
#define highpow(a) (1LL << (ll)lg(a))

using namespace std;

const ll LINF = 2e18;
struct Line{

    ll k, n;
    Line(ll _k = 0, ll _n = LINF){ k = _k; n = _n; }
    ll operator()(ll x) const { return k*x+n; }
};
class LiChao{

    ll L, R;
    vector<Line> tree;
    vector<array<int, 2> > ch;

    int Node(){ tree.pb(Line()); ch.pb({-1, -1}); return tree.size()-1; }

    int Child(int s, int i){ if (!~ch[s][i]){ int u = Node(); ch[s][i] = u; } return ch[s][i]; }

    void Insert(int s, int l, int r, Line f){
        int m = (l + r)>>1;
        if (f(m) < tree[s](m)) swap(tree[s], f);
        if (f(l) < tree[s](l)) Insert(Child(s, 0), l, m, f);
        if (f(r) < tree[s](r)) Insert(Child(s, 1), m+1, r, f);
    }

    ll Get(int s, int l, int r, ll x) const {
        if (!~s) return LINF;
        int m = (l + r)>>1;
        if (x <= m) return min(tree[s](x), Get(ch[s][0], l, m, x));
        else return min(tree[s](x), Get(ch[s][1], m+1, r, x));
    }

public:
    LiChao(ll l, ll r){ Assign(l, r); }
    void Assign(ll l, ll r){
        L = l; R = r;
        tree.clear(); ch.clear();
        Node();
    }
    void Insert(ll k, ll n){ Insert(0, L, R, Line(k, n)); }
    ll Get(ll x) const { return Get(0, L, R, x); }
};

const int mxN = 5e4+10, INF = 2e9;
ll n, m, dp[mxN][4005];
array<int, 2> a[mxN];

ll sq(ll x){ return x*x; }

ll take_photos(int n, int m, int k, vector<int> r, vector<int> c){

    for (int i = 0; i < n; i++)
        a[i] = {min(r[i], c[i]), max(r[i], c[i])};
    sort(a, a+n);
    vector<array<int, 2> > tmp;
    for (int i = 0, mx = -1; i < n; i++){
        if (a[i][1] > mx) tmp.pb(a[i]);
        smax(mx, a[i][1]);
    }
    a[0] = {-1, -1};
    for (int i = 0; i < tmp.size(); i++)
        a[i+1] = tmp[i];
    n = tmp.size();
    for (int i = 1; i <= n; i++)
        dp[i][0] = LINF;
    for (int j = 1; j <= k; j++){
        LiChao cht(0, 1e6);
        for (int i = 1; i <= n; i++){
            cht.Insert(-2 * (a[i][0] - 1), dp[i-1][j-1] + sq(a[i][0] - 1) - sq(max(0, a[i-1][1] - a[i][0] + 1)));
            dp[i][j] = sq(a[i][1]) + cht.Get(a[i][1]);
        }
    }
    ll ans = LINF;
    for (int i = 0; i <= k; i++)
        smin(ans, dp[n][i]);
    return ans;
}

Compilation message (stderr)

aliens.cpp: In function 'long long int take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:92:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::array<int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |     for (int i = 0; i < tmp.size(); i++)
      |                     ~~^~~~~~~~~~~~

• Subtask 1: 4 / 4
• Subtask 2: 12 / 12
• Subtask 3: 9 / 9
• Subtask 4: 16 / 16
• Subtask 5: 19 / 19
• Subtask 6: 0 / 40