Submission #471540

#	Time	Username	Problem	Language	Result	Execution time	Memory
471540		sofapuden	Aliens (IOI16_aliens)	C++14	4 / 100	1 ms	292 KiB

aliens

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

using namespace std;

typedef long long ll;

const ll INF = (1ll<<60);

bool cmp(pair<ll,ll> &a, pair<ll,ll> &b){
	if(a.first == b.first)return a.second > b.second;
	return a.first < b.first;

}

ll take_photos(int n, int m, int k, vector<int> r, vector<int> c) {
	vector<pair<ll,ll>> v(n);
	for(int i = 0; i < n; ++i){
		v[i] = {r[i],c[i]};
	}
	for(int i = 0; i < n; ++i){
		if(v[i].first > v[i].second)swap(v[i].first,v[i].second);
	}
	sort(v.begin(),v.end(),cmp);
	ll l = 0, ri = INF, ans = INF, bes, cnt;
	while(l <= ri){
		ll m = (l+ri)>>1;
		ll st = v[0].first, cu = v[0].second;
		ll su = (cu-st+1)*(cu-st+1);
		ll cn = 1;
		for(int i = 0; i < n; ++i){
			if(v[i].second <= cu)continue;
			ll un = 0;
			if(v[i].first <= cu){
				un = (cu-v[i].first+1)*(cu-v[i].first+1);
			}
			if((v[i].second-v[i].first+1)*(v[i].second-v[i].first+1)-un+(m*cn) <= (v[i].second-st+1)*(v[i].second-st+1)-(cu-st+1)*(cu-st+1)){
				cn++;
				su+=(v[i].second-v[i].first+1)*(v[i].second-v[i].first+1)-un;
				st = v[i].first;
				cu = v[i].second;
			}
			else{
				su+=(v[i].second-st+1)*(v[i].second-st+1)-(cu-st+1)*(cu-st+1);
				cu = v[i].second;
			}
		}
		if(cn <= k){
			cnt = cn;
			bes = m;
			ans = min(ans,su);
			ri = m-1;
		}
		else{
			l = m+1;
		}
	}
	return ans-(k-cnt)*bes;
}

Compilation message (stderr)

aliens.cpp: In function 'll take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:58:15: warning: 'cnt' may be used uninitialized in this function [-Wmaybe-uninitialized]
   58 |  return ans-(k-cnt)*bes;
      |             ~~^~~~~
aliens.cpp:58:20: warning: 'bes' may be used uninitialized in this function [-Wmaybe-uninitialized]
   58 |  return ans-(k-cnt)*bes;
      |             ~~~~~~~^~~~

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