Submission #342983

#	Time	Username	Problem	Language	Result	Execution time	Memory
342983		maskoff	Money (IZhO17_money)	C++14	0 / 100	2 ms	2284 KiB

money

#include <bits/stdc++.h>
 
#define file ""
 
#define all(x) x.begin(), x.end()
 
#define sc second
#define fr first
 
#define pb push_back
#define mp make_pair
 
using namespace std;
 
typedef long long ll;
typedef pair<int, int> pii;
 
const ll inf = 1e18 + 5;
const ll mod = 1e9 + 7;
 
const int N = 1e5 + 5;
 
int dx[] = {+1, 0, -1, 0};
int dy[] = {0, +1, 0, -1};
 
int n;
int a[N], l[N];
vector<int> t(N * 4, 1e9);
vector<int> dp(N + 5);
           
void update(int u, int l, int r, int pos, int val) {
 	if (l == r) {
 	 	t[u] = val;
		return;
 	}
 	int m = l + r >> 1;
 	if (pos <= m) update(u + u, l, m, pos, val);
 	else update (u + u + 1, m + 1, r, pos, val);
 	t[u] = min(t[u + u], t[u + u + 1]);
}

int get(int u, int ul, int ur, int l, int r) {
 	if (l > ur || ul > r) return 1e9;
 	if (l <= ul && ur <= r) return t[u];
 	int um = ul + ur >> 1;
 	return min(get(u + u, ul, um, l, r), get(u + u + 1, um + 1, ur, l, r));
}

int check(int lft, int rgt, int mx, int mn) {
	int pos = -1;
	int k = rgt;
	while (lft <= rgt) {
		int m = lft + rgt >> 1;
		if (a[m] == mn) pos = m, lft = m +1;
		if (a[m] > mn) rgt = m - 1;
		if (a[m] < mn) pos = m, lft = m + 1;
	}	
	if (a[pos] <= mn && a[pos] <= mx)
		return dp[rgt];
	else return 1e9;
}

            
int main() { 
	ios_base :: sync_with_stdio(false);               
	cin.tie(nullptr);
	srand(time(nullptr));
	cin >> n;
	for (int i = 1; i <= n; i++) cin >> a[i];

	l[1] = 1;
	int last = 1;
	for (int i = 2; i <= n; i++) {
   	if (a[i] >= a[i - 1])  continue;
  	else {
  		for (int p = last; p <= i - 1; p++)
  			l[p] = last;
  		last = i;
  	}
  }
  for (int p = last; p <= n; p++) l[p] = last;
  update(1, 1, n, 1, 0);
  dp[1] = 1;
  for (int i = 2; i <= n; i++) {
  	update(1, 1, n, i, dp[i - 1]);
  	dp[i] = get(1, 1, n, l[i], i) + 1;
  	if (l[i] == 1) {
  		dp[i] = 1;
  		continue;
  	}
  	//dp[i] = min(dp[i], check(l[l[i] - 1], l[i] - 1, a[i], a[l[i]]));
  }                                                           
  cout << dp[n];
  return 0;
}  

Compilation message (stderr)

money.cpp: In function 'void update(int, int, int, int, int)':
money.cpp:36:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   36 |   int m = l + r >> 1;
      |           ~~^~~
money.cpp: In function 'int get(int, int, int, int, int)':
money.cpp:45:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   45 |   int um = ul + ur >> 1;
      |            ~~~^~~~
money.cpp: In function 'int check(int, int, int, int)':
money.cpp:53:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   53 |   int m = lft + rgt >> 1;
      |           ~~~~^~~~~
money.cpp:51:6: warning: unused variable 'k' [-Wunused-variable]
   51 |  int k = rgt;
      |      ^

• Subtask 1: 0 / 9
• Subtask 2: 0 / 16
• Subtask 3: 0 / 20
• Subtask 4: 0 / 55