Submission #430363

#	Time	Username	Problem	Language	Result	Execution time	Memory
430363		patrikpavic2	The short shank; Redemption (BOI21_prison)	C++17	70 / 100	1929 ms	12732 KiB

prison

#include <cstdio>
#include <cstring>
#include <stack>
#include <vector>
 
#define X first
#define Y second
#define PB push_back
 
using namespace std;
 
const int N = 1e5 + 500;
const int OFF = (1 << 17);
 
typedef long long ll;
typedef pair < int, int > pii;
 
ll LO, HI = (ll)1e9, COST;
 
inline ll get_cost(pii &tmp){
	return 100000LL * tmp.X + COST * tmp.Y;
}
 
inline pii bolji(pii A, pii B){
	if(get_cost(A) < get_cost(B))
		return A;
	return B;
}
 
pii T[2 * OFF];
int prop[2 * OFF];
int n, d, tme[N], L;
vector < int > q[N];
 
void refresh(int x){
	if(!prop[x]) return;
	T[x].X += prop[x];
	if(x < OFF){
		prop[2 * x] += prop[x];
		prop[2 * x + 1] += prop[x];
	}
	prop[x] = 0;
}
 
void update(int i, int a, int b, int lo, int hi){
	refresh(i);
	if(lo <= a && b <= hi) {
		prop[i]++; refresh(i);
		return;
	}
	if(a > hi || b < lo) { return; }
	update(2 * i, a, (a + b) / 2, lo, hi);
	update(2 * i + 1, (a + b) / 2 + 1, b, lo, hi);
	T[i] = bolji(T[2 * i], T[2 * i + 1]);
}
 
void postavi(int i, int a, int b, int gdje, pii kog){
	refresh(i); refresh(i ^ 1);
	if(a == b){
		T[i] = kog; return;
	}
	if(gdje <= (a + b) / 2)
		postavi(2 * i, a, (a + b) / 2, gdje, kog);
	else
		postavi(2 * i + 1, (a + b) / 2 + 1, b, gdje, kog);
	T[i] = bolji(T[2 * i], T[2 * i + 1]);
}
 
pii dp[N];
 
pii probaj(){
	for(int i = 0;i < 2 * OFF;i++) T[i] = {N, N}, prop[i] = 0;
	postavi(1, 0, OFF - 1, 0, {0, 0});
	for(int i = 1;i <= n;i++){
		for(int j : q[i]){
			//printf("%d %d += 1\n", 0, j - 1);
			update(1, 0, OFF - 1, 0, j - 1);
		}
		dp[i] = T[1]; dp[i].Y++; postavi(1, 0, OFF - 1, i, dp[i]);
	//	printf("dp[ %d ] = %d %d\n", i, dp[i].X, dp[i].Y);
	}
	return T[1];
}
 
int main(){
	scanf("%d%d%d", &n, &d, &L);
	stack < int > Q;
	for(int i = 1;i <= n;i++){
		scanf("%d", tme + i);
		Q.push(i);
		while(!Q.empty() && tme[Q.top()] + i - Q.top() > L)
			Q.pop();
		if(!Q.empty()){
		//	printf("%d %d\n", Q.top(), i);
			q[i].PB(Q.top());
		}
	}
	for(int i = 0;i < 32;i++){
		COST = (LO + HI) / 2;
		int odg = probaj().Y;
		if(odg == d) break;
	//	printf("LO = %lld HI = %lld\n", LO, HI);
		if(odg < d)
			HI = COST;
		else
			LO = COST;
	}
	//printf("COST = %lld\n", COST);
	pii fin = probaj();
	//printf("%d %d\n", fin.X, fin.Y);
	printf("%lld\n", (get_cost(fin) - COST * d) / 100000LL);
	return 0;
}

Compilation message (stderr)

prison.cpp: In function 'int main()':
prison.cpp:86:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |  scanf("%d%d%d", &n, &d, &L);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
prison.cpp:89:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |   scanf("%d", tme + i);
      |   ~~~~~^~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 0 / 10
• Subtask 3: 20 / 20
• Subtask 4: 10 / 10
• Subtask 5: 25 / 25
• Subtask 6: 0 / 20