Cod sursa(job #2855577)

Utilizator norryna07Alexandru Norina norryna07 Data 22 februarie 2022 17:13:48
Problema Cautare binara Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1 kb
#include <fstream>
#define N 100005
using namespace std;

ifstream fin ("cautbin.in");
ofstream fout ("cautbin.out");

int a[N], n;

int last_x(int x)
{
    int st=1, dr=n, m;
    while (st<=dr)
    {
        m=(st+dr)/2;
        if (x<a[m]) dr=m-1;
        else st=m+1;
    }
    if (a[dr]==x) return dr;
    else return -1;
}

int last_sx(int x)
{
    int st=1, dr=n, m;
    while (st<=dr)
    {
        m=(st+dr)/2;
        if (x<a[m]) dr=m-1;
        else st=m+1;
    }
    return dr;
}

int first_bx(int x)
{
    int st=1, dr=n, m;
    while (st<=dr)
    {
        m=(st+dr)/2;
        if (x>a[m]) st=m+1;
        else dr=m-1;
    }
    return st;
}

int main()
{
    fin>>n;
    for (int i=1; i<=n; ++i) fin>>a[i];
    int m, x, tip;
    fin>>m;
    for (int i=1; i<=m; ++i)
    {
        fin>>tip>>x;
        if (tip==0) fout<<last_x(x)<<'\n';
        if (tip==1) fout<<last_sx(x)<<'\n';
        if (tip==2) fout<<first_bx(x)<<'\n';
    }
    return 0;
}