Submission #35769

#	Time	Username	Problem	Language	Result	Execution time	Memory
35769		funcsr	Money (IZhO17_money)	C++14	100 / 100	899 ms	18020 KiB

money

#include <cstdio>
#include <iostream>
#include <algorithm>
#include <string>
#include <cstring>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <cmath>
#include <iomanip>
#include <cassert>
#include <bitset>
using namespace std;

typedef pair<int, int> P;
#define rep(i, n) for (int i=0; i<(n); i++)
#define all(c) (c).begin(), (c).end()
#define uniq(c) c.erase(unique(all(c)), (c).end())
#define index(xs, x) (int)(lower_bound(all(xs), x) - xs.begin())
#define _1 first
#define _2 second
#define pb push_back
#define INF 1145141919
#define MOD 1000000007

#define MAX_N (1<<20)
int seg[MAX_N*2-1];
int query(int a, int b, int k=0, int l=0, int r=MAX_N) {
  if (b <= l || r <= a) return 0;
  if (a <= l && r <= b) return seg[k];
  return query(a, b, k*2+1, l, (l+r)/2) + query(a, b, k*2+2, (l+r)/2, r);
}
void add(int k) {
  k += MAX_N-1;
  if (seg[k]) return;
  seg[k]++;
  while (k > 0) {
    k = (k-1) / 2;
    seg[k]++;
  }
}
int kth(int x, int k=0, int l=0, int r=MAX_N) {
  if (r-l == 1) return l;
  if (x <= seg[k*2+1]) return kth(x, k*2+1, l, (l+r)/2);
  else return kth(x-seg[k*2+1], k*2+2, (l+r)/2, r);
}

int N;
int A[1000000];
int L[1000000];

signed main() {
  scanf("%d", &N);
  rep(i, N) scanf("%d", &A[i]);
  L[N-1] = N-1;
  for (int i=N-2; i>=0; i--) {
    if (A[i] <= A[i+1]) L[i] = L[i+1];
    else L[i] = i;
  }

  add(1000001);
  rep(i, N) {
    int s = query(0, A[i]+1);
    int lim = kth(s+1);
    L[i] = upper_bound(A+i, A+L[i]+1, lim) - A - 1;
    add(A[i]);
  }
  //rep(i, N) cout<<L[i] << ",";cout<<"\n";
  assert(is_sorted(L, L+N));
  rep(i, N) assert(L[i] >= i);
  int lo = 0, ctr = 0;
  while (lo < N) {
    lo = L[lo]+1;
    ctr++;
  }
  printf("%d\n", ctr);
  return 0;
}

Compilation message (stderr)

money.cpp: In function 'int main()':
money.cpp:54:18: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", &N);
                  ^
money.cpp:55:31: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   rep(i, N) scanf("%d", &A[i]);
                               ^

• Subtask 1: 9 / 9
• Subtask 2: 16 / 16
• Subtask 3: 20 / 20
• Subtask 4: 55 / 55