Submission #786961

#	Time	Username	Problem	Language	Result	Execution time	Memory
786961		LIF	Aliens (IOI16_aliens)	C++14	4 / 100	1 ms	596 KiB

aliens

#include "aliens.h"
#include<bits/stdc++.h>
#include<vector>
using namespace std;
int rr[300005];
int cc[300005];
int color[305][305];
int dp[1005][1005];
bool can[500005];
struct node
{
	int r;
	int c;
}nod[500005];
int nowr[300005];
int nowc[300005];
bool cmp(node x,node y)
{
	if(x.r == y.r)return x.c < y.c;
	else return x.r < y.r; 
}
double getk(int num1,int num2,int tim)
{
	int x1 = nod[num1+1].r;
	int x2 = nod[num2+1].r;
	int y1 = dp[num1][tim-1] + (nod[num1+1].r) * (nod[num1+1].r) - max(0,nod[num1].c - nod[num1+1].r + 1) * max(0,nod[num1].c - nod[num1+1].r + 1);
	int y2 = dp[num2][tim-1] + (nod[num2+1].r) * (nod[num2+1].r) - max(0,nod[num2].c - nod[num2+1].r + 1) * max(0,nod[num2].c - nod[num2+1].r + 1);
	if(x1 == x2)
	{
		return (y1-y2) / 1e-9;
	}	
	else
	{
		return (y1-y2) / (x1-x2);
	}
}
int q[300005];
long long take_photos(int n, int m, int k, std::vector<int> r, std::vector<int> c) {
	for(int i=0;i<r.size();i++)rr[i+1] = r[i];
	for(int i=0;i<c.size();i++)cc[i+1] = c[i];
	bool flag2 = true;
	for(int i=1;i<=n;i++)
	{
		if(rr[i] > cc[i])swap(rr[i],cc[i]);
		if(rr[i] != cc[i])flag2 = false;
	}
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=k;j++)dp[i][j] = 1e9;
		dp[i][0] = 1e9;
	}
	dp[0][0] = 0;
	for(int i=1;i<=n;i++)
	{
		nod[i].r = rr[i];
		nod[i].c = cc[i];
	}
	nod[0].r = -10000;
	nod[0].c = -10000;
	
	if(k == n && m <= 100)
	{
		for(int i=1;i<=n;i++)
		{
			for(int j=min(rr[i],cc[i]);j<=max(rr[i],cc[i]);j++)for(int k=min(rr[i],cc[i]);k<=max(rr[i],cc[i]);k++)color[j][k] = 1;
		}
		int cnt = 0;
		for(int i=0;i<=m-1;i++)for(int j=0;j<=m-1;j++)if(color[i][j] == 1)cnt++;
		return cnt;
	}
	for(int i=1;i<=n;i++)can[i] = true;
	for(int i=1;i<=n;i++)
	{
		for(int j=1;j<=n;j++)
		{
			if(rr[i] <= rr[j] && cc[j] <= cc[i] && i!=j && (rr[i] != rr[j] || cc[i] != cc[j]))can[j] = false;
		}
	}
	int num = 0;
	for(int i=1;i<=n;i++)
	{
		if(can[i] == false)continue;
		num++;
		nod[num].c = cc[i];
		nod[num].r = rr[i];
	}
	sort(nod+1,nod+num+1,cmp);
	for(int i=1;i<=num;i++)
	{
		dp[i][1] = (nod[i].c + 1) * (nod[i].c + 1);
	}
	
	for(int tim=2;tim<=k;tim++)
	{
		int h = 1;
		int t = 0;
		for(int i=1;i<=num;i++)
		{
			while(h < t && getk(i-1,q[t],tim) <= getk(q[t],q[t-1],tim))t--;
			q[++t] = i-1;
			while(h < t && getk(q[h+1],q[h],tim) <= 2 * (c[i]+1))h++;
			int j = q[h];
			
			int del = nod[j].c - nod[j+1].r + 1;
			int sub = max(0,del) * max(0,del);
			int add = (nod[i].c - nod[j+1].r + 1) * (nod[i].c - nod[j+1].r + 1);
		//	cout<<tim<<" "<<i<<" "<<j<<endl;
			dp[i][tim] = dp[j][tim-1] + add - sub;
		}
	}
	int ans = 1e9;
	for(int i=1;i<=num;i++)
	{
		for(int tim=1;tim<=k;tim++)
		{
			ans = min(ans,dp[i][tim]);
		}
	}
    return ans;
}

Compilation message (stderr)

aliens.cpp: In function 'long long int take_photos(int, int, int, std::vector<int>, std::vector<int>)':
aliens.cpp:39:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   39 |  for(int i=0;i<r.size();i++)rr[i+1] = r[i];
      |              ~^~~~~~~~~
aliens.cpp:40:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   40 |  for(int i=0;i<c.size();i++)cc[i+1] = c[i];
      |              ~^~~~~~~~~
aliens.cpp:41:7: warning: variable 'flag2' set but not used [-Wunused-but-set-variable]
   41 |  bool flag2 = true;
      |       ^~~~~

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