Cod sursa(job #2233060)

Utilizator Raoul_16Raoul Bocancea Raoul_16 Data 22 august 2018 01:24:32
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 1.98 kb
#include <fstream>
std::ifstream f("arbint.in");
std::ofstream g("arbint.out");
const int MAX = 1e5, INF = 0x3f3f3f3f;
int N, M, v[MAX + 5], St[4 * MAX + 5];
void query(int, int, int, int, int, int&);
void update(int, int, int, int, int);
void Build(int, int, int);
int main() {
    f >> N >> M;
    for (int i = 1; i <= N; ++i)
        f >> v[i];
    Build(1, 1, N);
    int quest;
    for (int i = 0; i < M; ++i){
        f >> quest;
        if (!quest) {
            int a, b;
            int answer = -INF;
            f >> a >> b;
            query(1, 1, N, a, b, answer);
            g << answer << "\n";
        }
        int value, position;
        if (quest == 1) {
            f >> position >> value;
            update(1, 1, N, position, value);
        }
    }
    return 0x0;
}
void Build(int node, int left, int right){
    if(left == right)
      St[node] = v[left];
    else {
        int mid = (left + right) / 2, leftSon = 2 * node, rightSon = leftSon + 1;
        Build(leftSon, left, mid);
        Build(rightSon, mid + 1, right);
        St[node] = std::max(St[leftSon], St[rightSon]);
    }
}
void update(int node, int left, int right, int pos, int val){
    if(left == right)
        St[node] = val;
    else {
        int mid = (left + right) / 2, leftSon = 2 * node, rightSon = leftSon + 1;
        if(pos <= mid)
            update(leftSon, left, mid, pos, val);
        else
            update(rightSon, mid + 1, right, pos, val);
        St[node] = std::max(St[leftSon], St[rightSon]);
    }
}
void query(int node, int left, int right, int queryL, int queryR, int& max){
    if(queryL <= left and right <= queryR)
        max = std::max(max, St[node]);
    else {
        int mid = (left + right) / 2, leftSon = 2 * node, rightSon = leftSon + 1;
        if (queryL <= mid)
            query(leftSon, left, mid, queryL, queryR, max);
        if (queryR > mid)
            query(rightSon, mid + 1, right, queryL, queryR, max);
    }
}