Cod sursa(job #627204)

Utilizator igsifvevc avb igsi Data 29 octombrie 2011 12:20:14
Problema Arbori de intervale Scor 50
Compilator cpp Status done
Runda Arhiva educationala Marime 1.31 kb
#include <cstdio>
using namespace std;
#define maximN 100001

int arb[5*maximN], m, n, maxim;

void actualizare(int nod, int st, int dr, int poz, int val){
    if(st == dr)    {
        arb[nod] = val;
        return;
    }
    int mij = (st+dr)/2;
    if(poz <= mij)
        actualizare(2*nod, st, mij, poz, val);
    else
        actualizare(2*nod+1, mij+1, dr, poz, val);
    arb[nod] = (arb[2*nod] <= arb[2*nod+1] ? arb[2*nod+1] : arb[2*nod]);
}

void interogare(int nod, int st, int dr, int a, int b){
    if(a <= st && dr <= b)
        maxim = (maxim <= arb[nod] ? arb[nod] : maxim);
    else{
        int mij = (st+dr) /2;
        if(a <= mij)
            interogare(2*nod, st, mij,a, b);
        if(mij < b)
            interogare(2*nod+1, mij+1, dr, a, b);
    }
}

int main(){
    freopen("arbint.in", "r", stdin);
    freopen("arbint.out", "w", stdout);
    scanf("%d %d", &n, &m);
    int op, a, b;

    for(int i = 1; i<=n; i++){
        scanf("%d", &a);
        actualizare(1, 1, n, i, a);
    }
    for(int i = 1; i<=m; i++){
        scanf("%d %d %d", &op, &a, &b);
        if(op == 0){
            maxim = 0;
            interogare(1, 1, n, a, b);
            printf("%d\n", maxim);
        }
        else
            actualizare(1, 1, n, a, b);
    }
    return 0;
}