Cod sursa(job #3265446)

Utilizator AlexandraVarutuValexandra AlexandraVarutu Data 30 decembrie 2024 11:39:25
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.42 kb
#include <fstream>
#include <climits>
#define dim 100001

using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n,m,a[4*dim];
int op,x,y,maxi;
void build_arbint(int nod,int st,int dr){
    if(st==dr){
        fin>>a[nod];
    }else{
        int mid=(st+dr)/2;
        build_arbint(2*nod,st,mid);
        build_arbint(2*nod+1,mid+1,dr);
        a[nod]=max(a[2*nod],a[2*nod+1]);
    }
}

void update(int nod, int st, int dr, int x, int val){//val din x se transforma in val
    if(st==dr){
        a[nod]=val;
    }else{
        int mid=(st+dr)/2;
        if(x<=mid){
            update(2*nod,st,mid,x,val);
        }
        if(x>mid){
            update(2*nod+1,mid+1,dr,x,val);
        }
        a[nod]=max(a[2*nod],a[2*nod+1]);
    }
}

void query(int nod, int st, int dr, int x, int y){
    if(x<=st&&dr<=y){//daca intervalul cautat cuprinde intervalul st dr
        maxi=max(maxi,a[nod]);
    }else{
        int mid=(st+dr)/2;
        if(x<=mid){
            query(2*nod,st,mid,x,y);
        }
        if(y>mid){
            query(2*nod+1,mid+1,dr,x,y);
        }
    }
}
int main()
{
    fin>>n>>m;
    build_arbint(1,1,n);
    for(int i=1;i<=m;i++){
        fin>>op>>x>>y;
        if(op==1){
            update(1,1,n,x,y);
        }else{
            maxi=INT_MIN;
            query(1,1,n,x,y);
            fout<<maxi<<'\n';
        }
    }
    return 0;
}