Submission #59712

#	Time	Username	Problem	Language	Result	Execution time	Memory
59712		KieranHorgan	Aliens (IOI16_aliens)	C++17	60 / 100	2106 ms	705260 KiB

aliens

#include "aliens.h"
#include <bits/stdc++.h>
using namespace std;
 
#define int long long
 
vector<pair<int, int>> intervals;
int cost(int i, int l) {
	int overlap = max(0ll, intervals[l].second-intervals[l+1].first+1);
	return (intervals[i].second-intervals[l+1].first+1)*(intervals[i].second-intervals[l+1].first+1) - overlap*overlap;
}
signed n;
vector<vector<int>> dp, opt;
int j;
void recurse(int l, int r) {
	if(l==r) return;
	int i = (l+r)/2;
	for(int cur = opt[j][l-1]; cur < (r==n+1?i:opt[j][r]+1); cur++) {
		if(dp[j-1][cur] + cost(i, cur) < dp[j][i]) {
			opt[j][i] = cur;
			dp[j][i] = dp[j-1][cur] + cost(i, cur);
		}
	}
	if(l+1 != r) {
		recurse(l, i);
		recurse(i+1, r);
	}
}

long long take_photos(signed N, signed m, signed k, vector<signed> r, vector<signed> c) {
	n=N;
	for(int i = 0; i < n; i++) {
		if(c[i] >= r[i])
			intervals.push_back({r[i], -c[i]});
		else
			intervals.push_back({c[i], -r[i]});
	}
	sort(intervals.begin(), intervals.end());
 
	auto interStore = intervals;
	intervals.clear();
	intervals.push_back({-1, -1});
	int ma = -1;
	for(auto p: interStore) {
		if(-p.second > ma) {
			ma = -p.second;
			intervals.push_back({p.first, -p.second});
		}
	}
 
 
	n = intervals.size()-1;
	k = min(k, n);
 
	dp.assign(k+1, vector<int>(n+1, 1ll<<60));
	opt.assign(k+1, vector<int>(n+1, 0));
	dp[0][0] = 0;

	// queue<pair<int, int>> ranges;
	for(j = 1; j <= k; j++) {
		recurse(1ll, (int)n+1);
	}
 
    return dp[k][n];
}

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