Submission #776238

#	Time	Username	Problem	Language	Result	Execution time	Memory
776238		faruk	Aliens (IOI16_aliens)	C++17	25 / 100	2033 ms	22356 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>
#define intsum(a) (a.second - a.first + 1LL) * (a.second - a.first + 1LL)
#define all(a) a.begin(), a.end()

using namespace std;

typedef long long ll;
typedef pair<ll, ll> pii;

const ll INF = 1e18;

bool cmp(pii a, pii b) {return pii(a.first, -a.second) < pii(b.first, -b.second);}

vector<pii> get_intervals(vector<int> r, vector<int> c) {
    vector<pii> all_intervals;
    for (int i = 0; i < r.size(); i++)
        all_intervals.push_back({min(r[i], c[i]), max(r[i], c[i])});
    sort(all(all_intervals), cmp);

    vector<pii> intervals;
    for (pii a : all_intervals) {
        if (intervals.size() == 0) {
            intervals.push_back(a);
        } else {
            pii last = *prev(intervals.end());
            if (last.second < a.second)
                intervals.push_back(a);
        }
    }
    return intervals;
}

long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
    vector<pii> ints = get_intervals(r, c);
    ints.insert(ints.begin(), pii(-1, -1));

    vector<vector<ll> > dp(k + 1, vector<ll>(ints.size() + 1, INF));
    dp[0][0] = 0;
    for (int i = 1; i <= k; i++) {
        dp[i][0] = 0;
        for (int j = 1; j < ints.size(); j++) {
            dp[i][j] = dp[i - 1][j];
            for (int l = 1; l <= j; l++) {
                ll cost = dp[i - 1][l - 1];
                cost += intsum(pii(ints[l].first, ints[j].second));

                pii intersection_interval(ints[l].first, ints[l - 1].second);
                if (intersection_interval.first <= intersection_interval.second)
                    cost -= intsum(intersection_interval);
                dp[i][j] = min(dp[i][j], cost);
            }
        }
    }

    return dp[k][ints.size() - 1];
}

Compilation message (stderr)

aliens.cpp: In function 'std::vector<std::pair<long long int, long long int> > get_intervals(std::vector<int>, std::vector<int>)':
aliens.cpp:17:23: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   17 |     for (int i = 0; i < r.size(); i++)
      |                     ~~^~~~~~~~~~
aliens.cpp: In function 'long long int take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:42:27: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, long long int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   42 |         for (int j = 1; j < ints.size(); j++) {
      |                         ~~^~~~~~~~~~~~~

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