Submission #107193

#	Time	Username	Problem	Language	Result	Execution time	Memory
107193		tictaccat	Aliens (IOI16_aliens)	C++14	25 / 100	2047 ms	7040 KiB

aliens

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

using namespace std;
typedef long long ll;

const ll INF = (ll)1e18;

ll take_photos(int n, int m, int k, vector<int> ri, vector<int> ci) {

    vector<pair<ll,ll>> points;
    for (int i = 0; i < n; i++) points.push_back(make_pair(max(ci[i],ri[i]),min(ri[i],ci[i])));
    sort(points.begin(),points.end());

    vector<ll> r,c; //such that r_i < r_j, c_i < c_j

    for (int i = 0; i < n; i++) {
        while (r.size() > 0 && points[i].second <= r.back()) {
            r.pop_back(); c.pop_back();
        }
        r.push_back(points[i].second); c.push_back(points[i].first);
    }

    n = r.size();

    //for (int i = 0; i < n; i++) cout << r[i] << " " << c[i] << "\n";

    vector<vector<ll>> dp(n+1, vector<ll> (k+1,INF)); //dp[i][k] = min squares covered over the first i points, using k segments

    for (int u = 0; u <= k; u++) dp[0][u] = 0;

    for (int i = 1; i <= n; i++) {
        for (int u = 1; u <= k; u++) {
            for (int j = 0; j < i; j++) {
                ll overlap;
                if (j == 0 || c[j-1] < r[j]) overlap = 0LL;
                else overlap = (c[j-1]-r[j]+1)*(c[j-1]-r[j]+1);
                ll area = (c[i-1]-r[j]+1)*(c[i-1]-r[j]+1);
                dp[i][u] = min(dp[i][u],dp[j][u-1] + area - overlap);
            }
        }
    }
   
   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