Submission #342710

#	Time	Username	Problem	Language	Result	Execution time	Memory
342710		maskoff	K blocks (IZhO14_blocks)	C++17	53 / 100	1084 ms	2988 KiB

blocks

#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};
 
struct line {
	int tag;
	int ans;
	int mx;
	int dp;
}	t[N * 4];
 
int a[N], l[N], n, k;
int dp[N]; 
 
void push(int u, int l, int r) {
 	if (l == r || t[u].tag == -1) return;
 	
 	t[u + u].mx = max(t[u].tag, t[u + u].mx);
 	t[u + u + 1].mx = max(t[u].tag, t[u + u + 1].mx);
 
 	t[u + u].ans = t[u + u].mx + t[u + u].dp;
 	t[u + u + 1].ans = t[u + u + 1].mx + t[u + u + 1].dp;
 
 	t[u + u].tag = max(t[u + u].tag, t[u].tag);
 	t[u + u + 1].tag = max(t[u + u + 1].tag, t[u].tag);

 	t[u].tag = -1;
}
 
void update_mx(int u, int ul, int ur, int l, int r, int val) {
	push(u, ul, ur);
	if (l > ur || ul > r) return;
	if (l <= ul && ur <= r) {
	 	t[u].mx = max(t[u].mx, val);
	 	t[u].ans = t[u].mx + t[u].dp;
	 	t[u].tag = max(t[u].tag, val);
	 	return;
 	}
 	int um = ul + ur >> 1;
 	update_mx(u + u, ul, um, l, r, val);
 	update_mx(u + u + 1, um + 1, ur, l, r, val);
 	t[u].ans = min(t[u + u].ans, t[u + u + 1].ans); 
}
 
void build(int u, int l, int r) {
 	t[u].tag = -1, t[u].mx = 0;
 	if (l == r) {
 		t[u].dp = dp[l - 1]; 
 		t[u].ans = dp[l - 1];
 		return;
 	}
 	int m = l + r >> 1;
 	build(u + u, l, m);
 	build(u + u + 1, m + 1, r);
 	t[u].ans = min(t[u + u].ans, t[u + u + 1].ans);
 	t[u].dp = min(t[u + u].dp, t[u + u + 1].dp);   
}
 
int get(int u, int ul, int ur, int l, int r) {
	push(u, ul, ur);
 	if (l > ur || ul > r) return 1e9;
 	if (l <= ul && ur <= r) return t[u].ans;
 	int um = ul + ur >> 1;
 	return min(get(u + u, ul, um, l, r), get(u + u + 1, um + 1, ur, l, r));
}
 
int main() {  
 
	ios_base :: sync_with_stdio(false);               
	cin.tie(nullptr);
	srand(time(nullptr));
	cin >> n >> k;
	a[0] = 1e9;
	for (int i = 1; i <= n; i++) cin >> a[i];
	int mx = 0;
	for (int i = 1; i <= n; i++) mx = max(mx, a[i]), dp[i] = mx;
	stack<int> s;
	s.push(0);
	for (int i = 1; i <= n; i++) {
	 	while (a[s.top()] <= a[i]) s.pop();
	 	l[i] = s.top() + 1;
	 	s.push(i);
	}
	build(1, 1, n);
	for (int block = 2; block <= k; block++) {
	 	for (int i = block; i <= n; i++) {
	 	 	update_mx(1, 1, n, l[i], i, a[i]);
	 	 	dp[i] = get(1, 1, n, block, i);
	 	}
	 	build(1, 1, n);
	}
	cout << dp[n];
  return 0;
}  

Compilation message (stderr)

blocks.cpp: In function 'void update_mx(int, int, int, int, int, int)':
blocks.cpp:60:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   60 |   int um = ul + ur >> 1;
      |            ~~~^~~~
blocks.cpp: In function 'void build(int, int, int)':
blocks.cpp:73:13: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   73 |   int m = l + r >> 1;
      |           ~~^~~
blocks.cpp: In function 'int get(int, int, int, int, int)':
blocks.cpp:84:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   84 |   int um = ul + ur >> 1;
      |            ~~~^~~~

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 0 / 47