Cod sursa(job #1099742)

Utilizator CosminRusuCosmin Rusu CosminRusu Data 6 februarie 2014 11:24:07
Problema Arbori de intervale Scor 100
Compilator cpp Status done
Runda Arhiva educationala Marime 3.46 kb
#include <fstream>
#include <iostream>
#include <vector>
#include <bitset>
#include <string.h>
#include <algorithm>
#include <iomanip>
#include <math.h>
#include <time.h>
#include <stdlib.h>
#include <set>
#include <map>
#include <string>
#include <queue>
#include <deque>

using namespace std;

const char infile[] = "arbint.in";
const char outfile[] = "arbint.out";

ofstream fout(outfile);

const int MAXN = 100001;
const int oo = 0x3f3f3f3f;

typedef vector<int> Graph[MAXN];
typedef vector<int> :: iterator It;

const inline int min(const int &a, const int &b) { if( a > b ) return b;   return a; }
const inline int max(const int &a, const int &b) { if( a < b ) return b;   return a; }
const inline void Get_min(int &a, const int b)    { if( a > b ) a = b; }
const inline void Get_max(int &a, const int b)    { if( a < b ) a = b; }

int arb[MAXN << 2], A[MAXN];

inline int leftSon(const int &Node) {
    return Node << 1;
}

inline int rightSon(const int &Node) {
    return (Node << 1) | 1;
}

void buildSegmentTree(const int &Node, const int &st, const int &dr) {
    if(st == dr) {
        arb[Node] = A[st];
        return;
    }
    int mid = ((st + dr) >> 1);
    buildSegmentTree(leftSon(Node), st, mid);
    buildSegmentTree(rightSon(Node), mid + 1, dr);
    arb[Node] = max(arb[leftSon(Node)], arb[rightSon(Node)]);
}

void UpdateSegmentTree(const int &Node, const int &st, const int &dr, const int &pos, const int &value) {
    if(st == dr) {
        arb[Node] = value;
        return;
    }
    int mid = ((st + dr) >> 1);
    if(pos <= mid)
        UpdateSegmentTree(leftSon(Node), st, mid, pos, value);
    else UpdateSegmentTree(rightSon(Node), mid + 1, dr, pos, value);
    arb[Node] = max(arb[leftSon(Node)], arb[rightSon(Node)]);
}

int QuerySegmentTree(const int &Node, const int &st, const int &dr, const int &x, const int &y) {
    if(x <= st && dr <= y)
        return arb[Node];
    int mid = ((st + dr)>>1);
    int ret = 0;
    if(x <= mid)
        ret = max(ret, QuerySegmentTree(leftSon(Node), st, mid, x, y));
    if(mid < y)
        ret=  max(ret, QuerySegmentTree(rightSon(Node), mid + 1, dr, x, y));
    return ret;
}


class Scanner {
  public:
    Scanner(string file, int buffer_size = 32768):
            buffer_size_(buffer_size) {
        file_ = fopen(file.c_str(), "r");
        buffer_ = new char[buffer_size];
        pointer_ = buffer_ + buffer_size_;
    }

    Scanner& operator>>(int &object) {
        object = 0;
        while (next() < '0' or next() > '9')
            advance();
        while (next() >= '0' and next() <= '9') {
            object = object * 10 + next() - '0';
            advance();
        }
        return *this;
    }

  private:
    char next() {
        if (pointer_ == buffer_ + buffer_size_) {
            pointer_ = buffer_;
            fread(buffer_, 1, buffer_size_, file_);
        }
        return *pointer_;
    }

    void advance() {
        ++pointer_;
    }

    FILE *file_;
    int buffer_size_;
    char *buffer_, *pointer_;
};
Scanner fin(infile);

int main() {
    int N, M;
    fin >> N >> M;
    for(int i = 1 ; i <= N ; ++ i)
        fin >> A[i];
    buildSegmentTree(1, 1, N);
    for(int i = 1 ; i <= M ; ++ i) {
        int op, x, y;
        fin >> op >> x >> y;
        if(op)
            UpdateSegmentTree(1, 1, N, x, y);
        else fout << QuerySegmentTree(1, 1, N, x, y) << '\n';
    }
    return 0;
}