Submission #621165

#	Time	Username	Problem	Language	Result	Execution time	Memory
621165		moyindavid	Fountain Parks (IOI21_parks)	C++17	Compilation error	0 ms	0 KiB

parks

#include <bits/stdc++.h>

using namespace std;

vector<bool> vis(200000,false);int cnt=0;vector<int> node[200000];vector<int> u,v,a,b;
void dsf(int i, vector<int> x, vector<int> y){
    vis[i]=true;
    cnt++;
    for(auto j: node[i]){
        if(!vis[j]){
            u.push_back(i);v.push_back(j);

            if(x[i]==x[j]){
                b.push_back((y[i]+y[j])/2);
                if(x[i]==2)a.push_back(x[i]-1);
                else a.push_back(x[i]+1);
            }
            else{
                a.push_back((x[i]+x[j])/2);
                b.push_back(y[i]-1);
            }
            dsf(j,x,y);
        }
    }
}

int construct_roads(vector<int> x, vector<int> y){


    map<pair<int,int>,bool> m;
    map<pair<int,int>,int> n;

    for(int i=0;i<x.size();i++){
        m[{x[i],y[i]}]=1;
        n[{x[i],y[i]}]=i;
    }

    for(int i=0;i<x.size();i++){
        if(m[{x[i]-2,y[i]}]){node[i].push_back(n[{x[i]-2,y[i]}]);node[n[{x[i]-2,y[i]}]].push_back(i);}
        if(m[{x[i]+2,y[i]}]){node[i].push_back(n[{x[i]+2,y[i]}]);node[n[{x[i]+2,y[i]}]].push_back(i);}
        if(m[{x[i],y[i]-2}]){node[i].push_back(n[{x[i],y[i]-2}]);node[n[{x[i],y[i]-2}]].push_back(i);}
        if(m[{x[i],y[i]+2}]){node[i].push_back(n[{x[i],y[i]+2}]);node[n[{x[i],y[i]+2}]].push_back(i);}
    }

    dsf(0,x,y);
    if(cnt==x.size()){
        build(u,v,a,b);
        return 1;
    }
    return 0;
}

Compilation message (stderr)

parks.cpp: In function 'int construct_roads(std::vector<int>, std::vector<int>)':
parks.cpp:33:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   33 |     for(int i=0;i<x.size();i++){
      |                 ~^~~~~~~~~
parks.cpp:38:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   38 |     for(int i=0;i<x.size();i++){
      |                 ~^~~~~~~~~
parks.cpp:46:11: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   46 |     if(cnt==x.size()){
      |        ~~~^~~~~~~~~~
parks.cpp:47:9: error: 'build' was not declared in this scope
   47 |         build(u,v,a,b);
      |         ^~~~~