Submission #389020

#	Time	Username	Problem	Language	Result	Execution time	Memory
389020		mehrdad_sohrabi	Aliens (IOI16_aliens)	C++14	60 / 100	273 ms	25652 KiB

aliens

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

/// 500 485 462 A4
using namespace std;
typedef long long int ll;
typedef complex<double> point;
typedef long double ld;
#define pb push_back
#define pii pair < ll , ll >
#define F first
#define S second
//#define endl '\n'
#define int long long
#define sync ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0)
#pragma GCC optimize("Ofast,no-stack-protector,unroll-loops,fast-math")
#define kill(x) return cout<<x<<'\n', 0;
const int N=5e4+10,M=1e6+100,inf=(ll)1e15;
ll dp[N][2];
ll A[M];
vector <pii> B;
void solve(ll l,ll r,ll L,ll R,ll k){
    if (r<l) return;
    ll mid=(r+l)/2;
    ll id=0,mx=inf;
    for (int i=L;i<=min(R,mid);i++){
        ll z=0;
        if (i>1){
            if (B[i-1].F<B[i-2].S){
                z=(B[i-2].S-B[i-1].F)*((B[i-2].S-B[i-1].F));
            }
        }
        ll x=dp[i-1][(k-1)%2]+(B[mid-1].S-B[i-1].F)*(B[mid-1].S-B[i-1].F)-z;
        if (mx>x){
            mx=x;
            id=i;
        }
    }
    dp[mid][k%2]=mx;
 //   cout << l << " " << r << " " << mid << " " << k << " " << mx << endl;
    solve(l,mid-1,L,id,k);
    solve(mid+1,r,id,R,k);
}
long long take_photos(int32_t n, int32_t m, int32_t k, std::vector<int32_t> r, std::vector<int32_t> c){
    for (int i=0;i<M;i++) A[i]=i;
    for (int i=0;i<n;i++){
        ll x=r[i],y=c[i];
        A[max(x,y)]=min(A[max(x,y)],min(x,y)-1);
    }
    for (int i=0;i<m;i++){
        if (A[i]<i){
            while(B.size() && B.back().F>=A[i]) B.pop_back();
            B.pb({A[i],i});
        }
    }
  //  for (auto u : B){
   //     cout << u.F << " " << u.S << endl;
    //}
    ll t=B.size();
    for (int i=1;i<=t;i++){
        dp[i][1]=(B[i-1].S-B[0].F)*(B[i-1].S-B[0].F);
    }
    for (int i=2;i<=k;i++){

        solve(1,t,1,t,i);
    }
    return dp[t][k%2];
}
/*
int32_t main() {
    int n, m, k;
    assert(3 == scanf("%d %d %d", &n, &m, &k));
    std::vector<int32_t> r(n), c(n);
    for (int i = 0; i < n; i++) {
        assert(2 == scanf("%d %d", &r[i], &c[i]));
    }
    long long ans = take_photos(n, m, k, r, c);


    printf("%lld\n", ans);
    return 0;
}
*/
/*
5 7 2
0 3
4 4
4 6
4 5
4 6
*/
//take_photos(5, 7, 2, [0, 4, 4, 4, 4], [3, 4, 6, 5, 6])

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