Cod sursa(job #1694695)

Utilizator oldatlantianSerban Cercelescu oldatlantian Data 25 aprilie 2016 19:56:24
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.18 kb
#include <algorithm>
#include <cstdio>
using namespace std;

int pom[500000];

void update(int nod, int st, int dr, int poz, int val) {
    if (st==dr) {
        pom[nod] = val;
        return;
    }
    int med = (st + dr) / 2;
    if(poz<=med) update(nod*2,  st, med, poz, val);
    else         update(nod*2+1, med+1, dr, poz, val);
    pom[nod]=max(pom[2*nod],pom[2*nod+1]);
}

int query(int nod, int st, int dr, int x, int y){
    if (x<=st && dr<=y)
        return pom[nod];
    int ans = 0, med = (st + dr) / 2;

    if(med >= x)
        ans = query(2*nod, st, med, x, y);
    if(med <  y)
        ans = max(query(2*nod+1, med+1, dr, x, y), ans);
    return ans;
}

int main(void){
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    int n,m,tsk,a,b,tmp;
    scanf("%d%d",&n,&m);
    for(int i=1; i<=n; ++i){
        scanf("%d",&tmp);
        update(1,1,n,i,tmp);
    }

    while(m--){
        scanf("%d%d%d",&tsk,&a,&b);
        switch(tsk){
        case 0:
            printf("%d\n",query(1,1,n,a,b));
            break;
        case 1:
            update(1,1,n,a,b);
            break;
        }
    }
    return 0;
}