Cod sursa(job #2158028)

Utilizator B_RazvanBaboiu Razvan B_Razvan Data 10 martie 2018 09:40:32
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.73 kb
#include <iostream>
#include <cstdio>
#define NMAX 100005
#define INF 0x3f3f3f3f

using namespace std;

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

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

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

void schimbVal(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) {
        schimbVal(a, b, 2 * poz, st, mij);
    }
    else {
        schimbVal(a, b, 2 * poz + 1, mij + 1, dr);
    }
    ai[poz] = max(ai[2 * poz],  ai[2 * poz + 1]);
}

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

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