Submission #824748

#	Time	Username	Problem	Language	Result	Execution time	Memory
824748		andrei_boaca	Fountain Parks (IOI21_parks)	C++17	30 / 100	389 ms	62256 KiB

parks

#include "parks.h"
#include <bits/stdc++.h>
//#include "grader.cpp"
using namespace std;

typedef pair<int,int> pii;
map<pii,int> ind;
map<pii,int> ocup;
map<pii,int> match;
struct point
{
    int x,y;
} v[200005];
int k;
vector<int> myy[200005];
vector<int> muchii[200005];
bool have[11][200005];
bool use[200005];
void dfs(int nod)
{
    use[nod]=1;
    for(int i:muchii[nod])
        if(!use[i])
            dfs(i);
}
int c[11][200005];
vector<int> U,V,A,B;
void addedge(int xa,int ya,int xb,int yb,int xc,int yc)
{
    int a=ind[{xa,ya}];
    int b=ind[{xb,yb}];
    U.push_back(a);
    V.push_back(b);
    muchii[a].push_back(b);
    muchii[b].push_back(a);
    A.push_back(xc);
    B.push_back(yc);
}
int construct_roads(std::vector<int> X, std::vector<int> Y)
{
    k=X.size();
    int xmax=0;
    for(int i=0;i<k;i++)
    {
        v[i]={X[i],Y[i]};
        ind[{X[i],Y[i]}]=i;
        xmax=max(xmax,X[i]);
        myy[X[i]].push_back(Y[i]);
        have[X[i]][Y[i]]=1;
    }
    if(xmax<=2)
    {
        sort(myy[2].begin(),myy[2].end());
        vector<int> U,V,a,b;
        for(int i=1;i<myy[2].size();i++)
        {
            if(myy[2][i]-myy[2][i-1]!=2)
                return 0;
            int x=2;
            int yu=myy[2][i-1];
            int yv=myy[2][i];
            U.push_back(ind[{x,yu}]);
            V.push_back(ind[{x,yv}]);
            a.push_back(x-1);
            b.push_back(yv-1);
        }
        build(U,V,a,b);
        return 1;
    }
    if(xmax<=4)
    {
        sort(myy[2].begin(),myy[2].end());
        sort(myy[4].begin(),myy[4].end());
        vector<int> U,V,A,B;
        for(int i=2;i<=200000;i+=2)
            if(have[2][i]&&have[2][i-2])
            {
                int a=ind[{2,i}];
                int b=ind[{2,i-2}];
                U.push_back(a);
                V.push_back(b);
                muchii[a].push_back(b);
                muchii[b].push_back(a);
                A.push_back(1);
                B.push_back(i-1);
            }
        for(int i=2;i<=200000;i+=2)
            if(have[4][i]&&have[4][i-2])
            {
                int a=ind[{4,i}];
                int b=ind[{4,i-2}];
                U.push_back(a);
                V.push_back(b);
                muchii[a].push_back(b);
                muchii[b].push_back(a);
                A.push_back(5);
                B.push_back(i-1);
            }
        for(int i=2;i<=200000;i+=2)
            if(have[2][i]&&have[4][i])
            {
                int a=ind[{2,i}];
                int b=ind[{4,i}];
                U.push_back(a);
                V.push_back(b);
                muchii[a].push_back(b);
                muchii[b].push_back(a);
                A.push_back(3);
                B.push_back(i+1);
            }
        dfs(0);
        for(int i=0;i<k;i++)
            if(!use[i])
                return 0;
        build(U,V,A,B);
        return 1;
    }
    if(xmax<=6)
    {
        sort(myy[2].begin(),myy[2].end());
        sort(myy[4].begin(),myy[4].end());
        sort(myy[6].begin(),myy[6].end());
        int nr=0;
        for(int i=2;i<=200000;i+=2)
            if(have[2][i])
            {
                if(have[2][i-2])
                {
                    addedge(2,i,2,i-2,1,i-1);
                    c[2][i]=c[2][i-2];
                }
                else
                {
                    nr++;
                    c[2][i]=nr;
                }
            }
        for(int i=2;i<=200000;i+=2)
            if(have[6][i])
            {
                if(have[6][i-2])
                {
                    addedge(6,i,6,i-2,7,i-1);
                    c[6][i]=c[6][i-2];
                }
                else
                {
                    nr++;
                    c[6][i]=nr;
                }
            }
        int lft=1;
        for(int i=2;i<=200000;i+=2)
            if(have[4][i])
            {
                if(have[4][i-2])
                {
                    if(lft==1)
                    {
                        addedge(4,i,4,i-2,3,i-1);
                        ocup[{3,i-1}]=1;
                    }
                    else
                    {
                        addedge(4,i,4,i-2,5,i-1);
                        ocup[{5,i-1}]=1;
                    }
                    lft^=1;
                    c[4][i]=c[4][i-2];
                }
                else
                {
                    lft=1;
                    nr++;
                    c[4][i]=nr;
                }
            }
        for(int i=2;i<=200000;i+=2)
            if(have[2][i]&&have[4][i])
            {
                int a=c[2][i];
                int b=c[4][i];
                if(match[{a,b}]==0)
                    {
                        match[{a,b}]=1;
                        if(!ocup[{3,i-1}])
                            {
                                addedge(2,i,4,i,3,i-1);
                                ocup[{3,i-1}]=1;
                            }
                        else
                        {
                            addedge(2,i,4,i,3,i+1);
                            ocup[{3,i+1}]=1;
                        }
                    }
            }
        for(int i=2;i<=200000;i+=2)
            if(have[4][i]&&have[6][i])
            {
                int a=c[4][i];
                int b=c[6][i];
                if(match[{a,b}]==0)
                    {
                        match[{a,b}]=1;
                        if(!ocup[{5,i-1}])
                            {
                                addedge(4,i,6,i,5,i-1);
                                ocup[{5,i-1}]=1;
                            }
                        else
                        {
                            addedge(4,i,6,i,5,i+1);
                            ocup[{5,i+1}]=1;
                        }
                    }
            }
        dfs(0);
        for(int i=0;i<k;i++)
            if(!use[i])
                return 0;
        build(U,V,A,B);
        return 1;
    }
}

Compilation message (stderr)

parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:55:22: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   55 |         for(int i=1;i<myy[2].size();i++)
      |                     ~^~~~~~~~~~~~~~
parks.cpp:225:1: warning: control reaches end of non-void function [-Wreturn-type]
  225 | }
      | ^

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 15 / 15
• Subtask 4: 0 / 20
• Subtask 5: 0 / 20
• Subtask 6: 0 / 30