Cod sursa(job #2934438)

Utilizator biancalautaruBianca Lautaru biancalautaru Data 5 noiembrie 2022 23:47:41
Problema Arbori de intervale Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.28 kb
#include <fstream>
#define DIM 100010
using namespace std;
ifstream fin("arbint.in");
ofstream fout("arbint.out");
int n,m,op,x,y,sol,v[DIM],a[4*DIM];

void build(int nod,int st,int dr) {
    if (st==dr)
        a[nod]=v[st];
    else {
        int mid=(st+dr)/2;
        build(2*nod,st,mid);
        build(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 poz,int val) {
    if (st==dr)
        a[nod]=val;
    else {
        int mid=(st+dr)/2;
        if (poz<=mid)
            update(2*nod,st,mid,poz,val);
        else
            update(2*nod+1,mid+1,dr,poz,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 && y>=dr)
        sol=max(sol,a[nod]);
    else {
        int mid=(st+dr)/2;
        if (x<=mid)
            query(2*nod,st,mid,x,y);
        if (y>=mid+1)
            query(2*nod+1,mid+1,dr,x,y);
    }
}

int main() {
    fin>>n>>m;
    for (int i=1;i<=n;i++)
        fin>>v[i];
    build(1,1,n);
    while (m--) {
        fin>>op>>x>>y;
        if (op==0) {
            sol=0;
            query(1,1,n,x,y);
            fout<<sol<<"\n";
        }
        else
            update(1,1,n,x,y);
    }
    return 0;
}