Cod sursa(job #2465365)

Utilizator AlexPascu007Pascu Ionut Alexandru AlexPascu007 Data 29 septembrie 2019 23:20:08
Problema Cele mai apropiate puncte din plan Scor 0
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.7 kb
#include <fstream>
#include <iomanip>
#include <cmath>
#include <algorithm>
#define DIM 100010
using namespace std;
ifstream fin("cmap.in");
ofstream fout("cmap.out");
int n;
pair<long long,long long> v[DIM],w[DIM],q[DIM];
long long dist(pair<long long,long long> x, pair<long long,long long> y){
    return (x.first-y.first)*(x.first-y.first)+(x.second-y.second)*(x.second-y.second);
}
void interclasare(int st, int mid, int dr) {
    int i=st;
    int j=mid+1;
    int k=0;
    while(i<=mid&&j<=dr)
        if(v[i].second<v[j].second)
            w[++k]=v[i++];
        else
            w[++k]=v[j++];
    for(;i<=mid;i++)
        w[++k]=v[i];
    for(;j<=dr;j++)
        w[++k]=v[j];
    for(k=1,i=st;i<=dr;i++,k++)
        v[i]=w[k];
}
long long solve(int st, int dr){
    long long r=0;
    if(dr-st==1) {
        r=dist(v[st],v[dr]);
        interclasare(st,st,dr);
        return r;
    }
    if(dr-st==2) {
        r=min(dist(v[st],v[st+1]),min(dist(v[st+1],v[dr]),dist(v[st],v[dr])));
        interclasare(st,st,st+1);
        interclasare(st,st+1,dr);
        return r;
    }
    int mid=(st+dr)/2;
    long long sol1=solve(st,mid);
    long long sol2=solve(mid+1,dr);
    interclasare(st,mid,dr);
    long long minim=min(sol1,sol2);
    int m=0;
    for(int i=st;i<=dr;i++)
        if(abs(v[mid].first-v[i].first)<=minim)
          q[++m]=v[i];
    for(int i=1;i<m;i++)
        for(int j=i+1;j<=m&&j<=i+7;j++)
            minim=min(minim,dist(q[i],q[j]));
    return minim;

}
int main(){
    fin>>n;
    for(int i=1;i<=n;i++)
        fin>>v[i].first>>v[i].second;
    sort(v+1,v+n+1);
    fout<<setpsolveision(7)<<fixed<<(double)sqrt(solve(1,n));
    return 0;
}