Cod sursa(job #2846178)

Utilizator Schweppesnick gurr Schweppes Data 8 februarie 2022 21:20:34
Problema Cautare binara Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.17 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin("cautbin.in");
ofstream fout("cautbin.out");
int lowerb(int a[],int x, int n){
    int st=1,dr=n,ans;
    int mij;
    while(st<=dr){
        mij=(st+dr)/2;
        if(a[mij]<=x)ans=mij,st=mij+1;
        else dr=mij-1;
    }
    return ans;
}
int upperb(int a[],int x, int n ){
    int st=1,dr=n,ans;
    int mij;
    while(st<=dr){
        mij=(st+dr)/2;
        if(x<=a[mij]) dr=mij-1,ans=mij;
        else st=mij+1;
    }
    return ans;
}

int bsearch0 (int a[], int n, int x)
{
    int m,poz=-1,st=1,dr=n;
    while(st<=dr)
    {
        m=(st+dr)/2;
        if(a[m]<=x){poz=m;
            st=m+1;
        }
        else dr=m-1;
    }
    if(a[poz]!=x)poz=-1;
    return poz;
}
int main(){
    int n,query,a[100005],cerr,x,st,dr,mij,poz;
    fin >> n;
    for(int i=1;i<=n;i++)fin>>a[i];
    fin>>query;
    for( ;query ;query--){
        fin >> cerr >> x;
        if(cerr==0){
            fout << bsearch0(a,n,x) << '\n';
        }
        else if(cerr==1){
            fout<<lowerb(a,x,n)<<'\n';
        }
        else fout << upperb(a,x,n) << '\n';
    }
    return 0;
}