Cod sursa(job #2883352)

Utilizator vladstefanVlad Oros vladstefan Data 1 aprilie 2022 13:58:10
Problema Arbori indexati binar Scor 50
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.58 kb

// problema aib
// solutie de 100p

#include <iostream>
#include <fstream>
#include <algorithm>
#include <cmath>
#include <cstring>
#include <string>
#include <vector>
#include <queue>
#include <stack>
#include <deque>

using namespace std;

#define NMax 100000

ifstream fin("aib.in");
ofstream fout("aib.out");

long long n, m;
long long v[NMax + 3], aib[2 * NMax + 3];

void input() {
    fin >> n >> m;
    for (long long i = 1; i <= n; ++i) fin >> v[i];
}

void init() {
    long long p;
    for (long long i = 1; i <= n; ++i) {
        aib[i] = v[i];
        p = i & (-i);
        for (long long k = 1; k < p; k *= 2) aib[i] += aib[i - k];
    }
}

void add(long long i, long long v) {
    for (long long k = i; k <= n; k += k & (-k)) aib[k] += v;
}

long long getsum(long long i) {
    long long s = 0;
    for (long long k = i; k; k -= k & (-k)) s += (long long)aib[k];
    return s;
}

void solve() {
    long long c, a, b;
    for (long long i = 1; i <= m; ++i) {
        fin >> c;
        if (c == 0) {
            fin >> a >> b;
            add(a, b);
        } else if (c == 1) {
            fin >> a >> b;
            fout << getsum(b) - getsum(a - 1) << '\n';
        } else {
            fin >> a;
            long long st = 1, dr = n, k = (st + dr) / 2;
            for (long long s = getsum(k); s != a && st <= dr; k = (st + dr) / 2, s = getsum(k)) {
                if (s < a) st = k + 1;
                else if (s > a) dr = k - 1;
            }
            if (getsum(k) != a) fout << "-1\n";
            else fout << k << '\n';
        }
    }
}

int main() {
    input();
    init();
    solve();
}