Cod sursa(job #1653038)

Utilizator AdrianGotcaAdrian Gotca AdrianGotca Data 15 martie 2016 18:10:49
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.31 kb
#include <fstream>

using namespace std;

int arb[1<<18];
int n,m,pos,val,st,dr,maxim;
void read();
void update(int,int,int);
void query(int,int,int);
int main(){
    read();
    return 0;
}

void read(){
    freopen("arbint.in","r",stdin);
    freopen("arbint.out","w",stdout);
    scanf("%d%d",&n,&m);
    for (int i=1;i<=n;i++){
        int x;
        scanf("%d",&x);
        pos=i,val=x;
        update(1,n,1);
    }
    for (int i=1;i<=m;i++){
        int x,a,b;
        scanf("%d%d%d",&x,&a,&b);
        if (x==0){
            maxim=-1;
            st=a;
            dr=b;
            query(1,n,1);
            printf("%d\n",maxim);
        }
        else {
            pos=a;
            val=b;
            update(1,n,1);
        }
    }
}

void update(int st,int dr,int n){
    if (st==dr){
        arb[n]=val;
        return;
    }
    int mij=(st+dr)/2;
    if (pos<=mij){
        update(st,mij,2*n);
    }
    else {
        update(mij+1,dr,2*n+1);
    }
    arb[n]=max(arb[2*n],arb[2*n+1]);
}

void query(int start,int stop,int n){
    if (st<=start&&stop<=dr){
        maxim=max(maxim,arb[n]);
        return;
    }
    int mij=(start+stop)/2;
    if (st<=mij){
        query(start,mij,2*n);
    }
    if (mij<dr){
        query(mij+1,stop,2*n+1);
    }
}