Submission #45972

#	Time	Username	Problem	Language	Result	Execution time	Memory
45972		RezwanArefin01	Aliens (IOI16_aliens)	C++17	25 / 100	2047 ms	7668 KiB

aliens

#include <bits/stdc++.h>
#include "aliens.h"
using namespace std;

typedef long long ll; 
typedef pair<int, int> ii;

#define sq(a) ((ll)(a) * (a))
#define cost(j, i) (sq(r[i] - l[j + 1] + 1) - sq(max(0, r[j] - l[j + 1] + 1)))

ll take_photos(int n, int m, int K, vector<int> R, vector<int> C) {
	vector<ii> tmp; 
	for(int i = 0; i < n; i++) {
		if(R[i] > C[i]) swap(R[i], C[i]); 
		tmp.emplace_back(C[i], R[i]);
	}
	sort(tmp.begin(), tmp.end());
	tmp.erase(unique(tmp.begin(), tmp.end()), tmp.end());
	vector<int> l = {-1}, r = {-1};
	for(ii seg : tmp) {
		if(seg.first == r.back()) continue; 
		while(l.size() && seg.second <= l.back() && r.back() <= seg.first) 
			r.pop_back(), l.pop_back();
		l.push_back(seg.second); 
		r.push_back(seg.first);
	}	

	n = l.size() - 1; 
	ll dp[K + 1][n + 1]; 
	memset(dp, 63, sizeof dp); 

	for(int i = 1; i <= n; i++) 
		dp[1][i] = sq(r[i] - l[1] + 1); 

	for(int k = 2; k <= K; k++) {
		for(int i = 1; i <= n; i++) {
			for(int j = 1; j < i; j++) {
				dp[k][i] = min(dp[k][i], dp[k - 1][j] + sq(r[i] - l[j + 1] + 1) - 
												sq(max(0, r[j] - l[j + 1] + 1)) );
			}
		}
	}

	ll ret = 1e18;
	for(int i = 1; i <= K; i++) ret = min(ret, dp[i][n]); 
	return ret;
}

#ifdef LOCAL_TESTING
int main() {
	freopen("in", "r", stdin);
    int n, m, k;
    assert(3 == scanf("%d %d %d", &n, &m, &k));
    std::vector<int> r(n), c(n);
    for (int i = 0; i < n; i++) {
        assert(2 == scanf("%d %d", &r[i], &c[i]));
    }
    ll ans = take_photos(n, m, k, r, c);
    
    printf("%lld\n", ans);
    return 0;
}
#endif

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