Submission #1037935

#	Time	Username	Problem	Language	Result	Execution time	Memory
1037935		Alihan_8	Aliens (IOI16_aliens)	C++17	25 / 100	2062 ms	37260 KiB

aliens

#include "aliens.h"

#include <bits/stdc++.h>

using namespace std;

#define all(x) x.begin(), x.end()
#define ar array
#define pb push_back
#define ln '\n'
//#define int long long

using i64 = long long;

template <class F, class _S>
bool chmin(F &u, const _S &v){
    bool flag = false;
    if ( u > v ){
        u = v; flag |= true;
    }
    return flag;
}

template <class F, class _S>
bool chmax(F &u, const _S &v){
    bool flag = false;
    if ( u < v ){
        u = v; flag |= true;
    }
    return flag;
}

const i64 inf = 1e15;

const int C = 1e6;

struct Lichao{
	struct Line{
		int m; i64 c;
		
		Line(int m = 0, i64 c = inf) : m(m), c(c) {}
		
		i64 operator ()(int x){ return m * 1LL * x + c; } 
	};
	
	struct Info{
		Line s;
		
		Info *lf, *rg;
		
		Info(Line s) : s(s), lf(0), rg(0) {}
	};
	
	Info *root = new Info({0, inf});
	
	void ins(Info *v, int l, int r, Line nw){
		if ( l == r ){
			if ( v -> s(l) > nw(l) ){
				v -> s = nw;
			}
			
			return;
		}
		
		int m = (l + r) / 2;
		
		if ( v -> s.m < nw.m ) swap(v -> s, nw);
		
		if ( v -> s(m) < nw(m) ){
			if ( v -> rg ){
				ins(v -> rg, m + 1, r, nw);
			} else v -> rg = new Info(nw);
		} else{
			swap(v -> s, nw);
			
			if ( v -> lf ){
				ins(v -> lf, l, m, nw);
			} else v -> lf = new Info(nw);
		}
	}
	
	void ins(Line nw){ ins(root, 0, C, nw); } 
	
	i64 get(Info *v, int l, int r, i64 x){
		if ( l == r ){
			return v -> s(x);
		}
		
		i64 m = (l + r) / 2, ret = v -> s(x);
		
		if ( v -> lf ) chmin(ret, get(v -> lf, l, m, x));
		
		if ( v -> rg ) chmin(ret, get(v -> rg, m + 1, r, x));
		
		return ret;
	}
	
	i64 get(i64 x){ return get(root, 0, C, x); } 
};


long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
	vector <int> a, f;
	
	{ // deleting unnecessary ones
		vector <int> g(m, m);
	
		for ( int i = 0; i < n; i++ ){
			int x = max(r[i], c[i]);
			
			chmin(g[x], min(r[i], c[i]));
		}
		
		vector <int> nxt;
		
		for ( int i = m - 1; i >= 0; i-- ){
			g[i] = i - g[i] + 1;
			
			if ( g[i] <= 0 ) continue;
			
			if ( nxt.empty() || nxt.back() - g[nxt.back()] > i - g[i] ){
				nxt.pb(i); f.pb(g[i]);
			} 
		} 
		
		nxt.pb(-1), f.pb(-1); // random stuff
		
		reverse(all(nxt));
		reverse(all(f));
		
		swap(a, nxt);
		
		n = (int)a.size() - 1;
	}
	
	vector <i64> h(n + 1), q(n + 1);
	
	for ( int i = 1; i <= n; i++ ){
		h[i] = -a[i] + f[i];
		
		if ( i > 1 ){
			q[i] = a[i - 1] + h[i];
			
			chmax(q[i], 0);
			
			q[i] *= q[i];
		}
	}
	
	vector <vector<i64>> dp(n + 1, vector <i64> (k + 1, inf));
	
	vector <Lichao> lch(k + 1);
	
	for ( int i = 0; i <= k; i++ ){
		dp[0][i] = 0;
	}
	
	for ( int i = 1; i <= n; i++ ){
		for ( int g = 1; g <= k; g++ ){
			lch[g].ins({2 * (int)h[i], dp[i - 1][g - 1] + h[i] * 1LL * h[i] - q[i]});
		}
	
		for ( int g = k; g > 0; g-- ){
			dp[i][g] = lch[g].get(a[i]) + a[i] * 1LL * a[i];
			
			continue;
			
			for ( int j = i; j > 0; j-- ){
				chmin(dp[i][g], dp[j - 1][g - 1] + h[j] * 1LL * h[j] + a[i] * 1LL * a[i] + 2LL * h[j] * a[i] - q[j]);
			}
		}
	}
	
	return dp[n][k];
}

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