Cod sursa(job #2126435)

Utilizator B_RazvanBaboiu Razvan B_Razvan Data 9 februarie 2018 17:04:59
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.72 kb
#include <iostream>
#include <cstdio>
#define NMAX 100005
#define INF 0x3f3f3f
using namespace std;

int N, M, v[NMAX], ai[NMAX * 5];

void read()
{
    scanf("%d %d", &N, &M);
    for(int i=1; i<=N; ++i)
        scanf("%d", &v[i]);
}

void build(int poz, int st, int dr)
{
    if(st == dr)
    {
        ai[poz] = v[st];
        return;
    }
    int mij = (st + dr) / 2;
    build(2 * poz, st, mij);
    build(2 * poz + 1, mij + 1, dr);
    ai[poz] = max(ai[2 * poz], ai[2 * poz + 1]);
}

void maximInterval(int a, int b, int &sol, int poz, int st, int dr)
{
    if(a <= st && dr <= b)
    {
        sol = max(sol, ai[poz]);
        return;
    }
    int mij = (st + dr) / 2;
    if(mij >= a)
        maximInterval(a, b, sol, 2 * poz, st, mij);
    if(mij < b)
        maximInterval(a, b, sol, 2 * poz + 1, mij + 1, dr);
}

void schimbareElement(int a, int b, int poz, int st, int dr)
{
    if(st == dr)
    {
        ai[poz] = b;
        return;
    }
    int mij = (st + dr) / 2;
    if(a <= mij)
        schimbareElement(a, b, 2 * poz, st, mij);
    else
        schimbareElement(a, b, 2 * poz + 1, mij + 1, dr);
    ai[poz] = max(ai[2 * poz], ai[2 * poz + 1]);
}

void solve()
{
    for(int i=1; i<=M; ++i)
    {
        int operatie, a, b;
        scanf("%d %d %d", &operatie, &a, &b);
        if(operatie == 0)
          {
              int sol = -1 * INF;
              maximInterval(a, b, sol, 1, 1, N);
              printf("%d\n", sol);
          }
        else
            schimbareElement(a, b, 1, 1, N);
    }
}


int main()
{
    freopen("arbint.in", "r", stdin);
    freopen("arbint.out", "w", stdout);
    read();
    build(1, 1, N);
    solve();
    return 0;
}