Cod sursa(job #3248870)

Utilizator Dragos__1_1Dragos Antohi Dragos__1_1 Data 13 octombrie 2024 15:53:34
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.4 kb
#include <bits/stdc++.h>
using namespace std;
ifstream f("arbint.in");
ofstream g("arbint.out");
long long v[100002],arb[400009],n,type,q,a,b,i;
void init (int index, int st, int dr){
    if (st==dr){
        arb[index]=v[st];
    }
    else{
        int mid=(st+dr)/2;
        init(index*2,st,mid);
        init(index*2+1,mid+1,dr);
        arb[index]=max(arb[index*2],arb[index*2+1]);

    }
}
void update (int index, int st, int dr, int a, int b){
    if (st==dr&&st==a){
        arb[index]=b;
    }
    else {
        int mid=(st+dr)/2;
        if (a<=mid){
            update(index*2,st,mid,a,b);
        }
        else{
            update(index*2+1,mid+1,dr,a,b);
        }
        arb[index]=max(arb[index*2+1],arb[index*2]);


    }
}
long long MAX(int index, int st, int dr, int a, int b){
    if (a<=st&&dr<=b){
        return arb[index];

    }
    else {
        int mid=(st+dr)/2;
        long long s1=0,s2=0;
        if (a<=mid){
            s1=MAX(index*2,st,mid,a,b);
        }
        if (mid<b){
            s2=MAX(index*2+1,mid+1,dr,a,b);
        }
        return max(s1,s2);
    }
}
int main()
{
    f>>n>>q;
    for (i=1;i<=n;i++)f>>v[i];
    init (1,1,n);
    while (q--){
        f>>type>>a>>b;
        if (type==0){
            g<<MAX(1,1,n,a,b)<<'\n';
        }
        else {
            update(1,1,n,a,b);
        }
    }
    return 0;
}