Submission #775759

#	Time	Username	Problem	Language	Result	Execution time	Memory
775759		DobromirAngelov	Quality Of Living (IOI10_quality)	C++14	100 / 100	2348 ms	141492 KiB

quality

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

using namespace std;

const int MAXN=3005;
const int INF=1e9+5;

int n,m;
int h,w;
int half;
int pref[MAXN][MAXN];
int minPoss1[MAXN][MAXN];
int minPoss2[MAXN][MAXN];

bool check(int x,int q[][3001])
{
    pref[0][0]=0;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            if(i>0 && j>0) pref[i][j]=pref[i-1][j]+pref[i][j-1]-pref[i-1][j-1];
            else if(i>0) pref[i][j]=pref[i-1][j];
            else if(j>0) pref[i][j]=pref[i][j-1];
            if(q[i][j]<x) pref[i][j]++;

            if(i>=h-1 && j>=w-1)
            {
                int a1=0,a2=0,b=0;
                if(i>=h) a1=pref[i-h][j];
                if(j>=w) a2=pref[i][j-w];
                if(i>=h && j>=w) b=pref[i-h][j-w];
                if(pref[i][j]-a1-a2+b>=half) return 1;
            }
        }
    }

    return 0;
}

int find_ans(int x,int q[][3001])
{
    deque<int> dq;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            while(!dq.empty() && dq.front()<=j-w) dq.pop_front();
            if(q[i][j]>=x)
            {
                while(!dq.empty() && q[i][j]<q[i][dq.back()]) dq.pop_back();
                dq.push_back(j);
            }
            if(!dq.empty()) minPoss1[i][j]=q[i][dq.front()];
            else minPoss1[i][j]=INF;
        }
        while(!dq.empty()) dq.pop_back();
    }

    for(int j=0;j<m;j++)
    {
        for(int i=0;i<n;i++)
        {
            while(!dq.empty() && dq.front()<=i-h) dq.pop_front();
            if(minPoss1[i][j]>=x)
            {
                while(!dq.empty() && minPoss1[i][j]<minPoss1[dq.back()][j]) dq.pop_back();
                dq.push_back(i);
            }
            if(!dq.empty()) minPoss2[i][j]=minPoss1[dq.front()][j];
            else minPoss2[i][j]=INF;
        }
        while(!dq.empty()) dq.pop_back();
    }

    int ans=INF;
    pref[0][0]=0;
    for(int i=0;i<n;i++)
    {
        for(int j=0;j<m;j++)
        {
            if(i>0 && j>0) pref[i][j]=pref[i-1][j]+pref[i][j-1]-pref[i-1][j-1];
            else if(i>0) pref[i][j]=pref[i-1][j];
            else if(j>0) pref[i][j]=pref[i][j-1];
            if(q[i][j]<x) pref[i][j]++;

            if(i>=h-1 && j>=w-1)
            {
                int a1=0,a2=0,b=0;
                if(i>=h) a1=pref[i-h][j];
                if(j>=w) a2=pref[i][j-w];
                if(i>=h && j>=w) b=pref[i-h][j-w];
                if(pref[i][j]-a1-a2+b>=half) ans=min(ans, minPoss2[i][j]);
            }
        }
    }

    return ans;
}

int rectangle(int R,int C,int H,int W,int q[3001][3001])
{
    n=R, m=C;
    h=H, w=W;
    half=h*w/2;
    int l=1,r=n*m;
    while(l<r)
    {
        int mid=(l+r)/2;
        if(check(mid,q)) r=mid;
        else l=mid+1;
    }

    return find_ans(l,q);
}

• Subtask 1: 20 / 20
• Subtask 2: 20 / 20
• Subtask 3: 20 / 20
• Subtask 4: 20 / 20
• Subtask 5: 20 / 20