Cod sursa(job #2778740)

Utilizator alexdumitruAlexandru Dumitru alexdumitru Data 2 octombrie 2021 08:53:55
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.12 kb
#include <bits/stdc++.h>
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n,m,i,v[100005],ar[400005],op,a,b;
int mymax(int a, int b){return a>=b?a:b;}
void build(int nod, int st, int dr)
{
    if(st==dr)ar[nod]=v[st];
    else {
        int m=st+(dr-st)/2;
        build(nod*2,st,m);
        build(nod*2+1,m+1,dr);
        ar[nod]=mymax(ar[nod*2],ar[nod*2+1]);
    }
}
int maxim(int nod, int a, int b, int l, int r)
{
    if(a<=l&&r<=b)return ar[nod];
    int max1=0,max2=0,m=l+(r-l)/2;
    if(a<=m)max1=maxim(nod*2,a,b,l,m);
    if(m<b)max2=maxim(nod*2+1,a,b,m+1,r);
    return mymax(max1,max2);
}
void update(int nod, int a, int l, int r, int b)
{
    if(l==r)ar[nod]=b;
    else {
        int m=l+(r-l)/2;
        if(a<=m)update(nod*2,a,l,m,b);
        else update(nod*2+1,a,m+1,r,b);
        ar[nod]=mymax(ar[nod*2],ar[nod*2+1]);
    }
}
int main()
{
    fin>>n>>m;
    for(i=1;i<=n;i++)fin>>v[i];
    build(1,1,n);
    while(m--)
    {
        fin>>op>>a>>b;
        if(!op)fout<<maxim(1,a,b,1,n)<<'\n';
        else update(1,a,1,n,b);
    }
    return 0;
}