Submission #912863

#	Time	Username	Problem	Language	Result	Execution time	Memory
912863		Faisal_Saqib	Ideal city (IOI12_city)	C++17	32 / 100	94 ms	1340 KiB

city

#pragma once
#include <vector>
#include <stdio.h>
#include <stdlib.h>
#include <algorithm>
#include <assert.h>
#include <iostream>
#include <cmath>
#include <queue>
using namespace std;
/*
1	11	N <= 2e2 O(n^2)
2	21	N <= 2e3 O(n^2)
3	23	N <= 1e5
4	45	N <= 1e5
For 3 any two cell such x[i]<=x[j] then for all x such that x[i]<=x<=x[j] there is non empty cell there
*/
const int N=2001;
vector<int> ma[N];
bool vis[N];
int h[N];
int DistanceSum(int n, int x[], int y[])
{
	if(n<=2000)
	{
		for(int i=0;i<n;i++)
		{
			for(int j=i+1;j<n;j++)
			{
				if((abs(x[i]-x[j])+abs(y[i]-y[j]))==1)
				{
					ma[i].push_back(j);
					ma[j].push_back(i);
				}
			}
		}
		long long ans1=0;
		long long mod=1e9;
		for(int i=0;i<n;i++)
		{
			for(int j=0;j<n;j++)
			{
				h[j]=0;
				vis[j]=0;
			}
			queue<int> q;
			q.push(i);
			vis[i]=1;
			long long ans=0;
			while(q.size())
			{
				int x=q.front();
				ans+=(long long)h[x];
				q.pop();
				for(int y:ma[x])
				{
					if(!vis[y])
					{
						vis[y]=1;
						h[y]=h[x]+1;
						q.push(y);
					}
				}
			}
			ans1+=ans;
		}
		ans1/=2;
		return ans1%mod;
	}
	long long other=0;
	long long mod=1e9;
	sort(x,x+n);
	sort(y,y+n);
	long long tot=0;
	for(int i=0;i<n;i++)
		tot+=x[i];
	long long pr=0;
	for(int i=0;i<n;i++)
	{
		pr+=x[i];
		tot-=x[i];
		other+=(((i+1)*x[i])-pr);
		other+=(tot-((n-i-1)*x[i]));
	}
  long long sm=(other/2)%mod;
	tot=0;
	pr=0;
  other=0;
	for(int j=0;j<n;j++)
	{
		tot+=y[j];
	}
	for(int i=0;i<n;i++)
	{
		pr+=y[i];
		tot-=y[i];
		other+=(((i+1)*y[i])-pr);
		other+=(tot-((n-i-1)*y[i]));
	}
	other/=2;
  other%=mod;
	return (other+sm)%mod;
}

Compilation message (stderr)

city.cpp:1:9: warning: #pragma once in main file
    1 | #pragma once
      |         ^~~~

• Subtask 1: 11 / 11
• Subtask 2: 21 / 21
• Subtask 3: 0 / 23
• Subtask 4: 0 / 45