Cod sursa(job #2272713)

Utilizator mouse_wirelessMouse Wireless mouse_wireless Data 30 octombrie 2018 16:43:42
Problema Arbori indexati binar Scor 100
Compilator cpp-64 Status done
Runda Arhiva educationala Marime 1.85 kb
#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
#define mp make_pair
#define CHECK(x) if(!(x)) return false;
#define CHECKRET(x, y) if(!(x)) return (y);
#define SKIP(x) if((x)) continue;
typedef pair<int, int> pii;

#ifdef INFOARENA
#define ProblemName "aib"
#else
#define ProblemName "fis"
#endif

#define InFile ProblemName ".in"
#define OuFile ProblemName ".out"

const int MAXN = 100010;
int arb[MAXN];
int N;

int query(int pos) {
  int l = 0, r = N;
  int ans = 0;
  while (l < r) {
    int mid = (l + r) / 2;
    if (pos < mid) r = mid;
    else {
      ans += arb[mid];
      l = mid + 1;
      if (l < r) ans -= arb[(l + r) / 2];
    }
  }
  return ans;
}

inline int qft(int l, int r) {
  int ans = query(r);
  if (l > 0) ans -= query(l - 1);
  return ans;
}

void update(int pos, int x) {
  int l = 0, r = N;
  while (l < r) {
    int mid = (l + r) / 2;
    arb[mid] += x;
    if (mid == pos) return;
    if (pos < mid) r = mid;
    else l = mid + 1;
  }
}

int query2(int x) {
  int l = 0, r = N;
  int ans = 0;
  while (l < r) {
    int mid = (l + r) / 2;
    int cur = arb[mid] - (mid + 1 < r ? arb[(mid + 1 + r) / 2] : 0);
    if (ans + cur == x) return mid;
    if (ans + cur < x) {
      l = mid + 1;
      ans += cur;
    }
    else r = mid;
  }
  return -2;
}

int main() {
  assert(freopen(InFile, "r", stdin));
  assert(freopen(OuFile, "w", stdout));
  int M;
  scanf("%d%d", &N, &M);
  for (int i = 0; i < N; ++i) {
    int x;
    scanf("%d", &x);
    update(i, x);
  }
  while (M--) {
    int qt;
    scanf("%d", &qt);
    if (qt == 0) {
      int a, x;
      scanf("%d%d", &a, &x);
      --a;
      update(a, x);
    }
    else if (qt == 1) {
      int l, r;
      scanf("%d%d", &l, &r);
      --l, --r;
      printf("%d\n", qft(l, r));
    }
    else {
      int x;
      scanf("%d", &x);
      printf("%d\n", query2(x) + 1);
    }
  }
  return 0;
}