Submission #428272

#	Time	Username	Problem	Language	Result	Execution time	Memory
428272		patrikpavic2	The short shank; Redemption (BOI21_prison)	C++17	0 / 100	83 ms	12996 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)1e12, 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;
}
 
int n, d, tme[N], L;
int par[N];
vector < int > q[N];
 
int pr(int x){
	if(par[x] == x) return x;
	return par[x] = pr(par[x]);
}
 
pii dp[N];
int dod[N];
 
pii probaj(){
	for(int i = 0;i <= n;i++) dod[i] = 0, dp[i] = {0,0};
	int mini = 0, pos = 0; dp[0] = {0, 0};
	for(int i = 1;i <= n;i++){
		for(int j : q[i]){
			//printf("%d %d += 1\n", 0, j - 1);
			if(j > mini)
				dod[j]++, pos++;
			while(mini + 1 < i && 
					100000LL * dp[mini].X + COST * dp[mini].Y >=
					100000LL * (dp[mini + 1].X - dod[mini + 1]) + COST * dp[mini + 1].Y){
				pos -= dod[++mini];
			}
		}
		//printf("mini = %d\n", mini);
		dp[i] = dp[mini]; dp[i].X += pos, dp[i].Y++;
		while(mini + 1 <= i && 
				100000LL * dp[mini].X + COST * dp[mini].Y >=
				100000LL * (dp[mini + 1].X - dod[mini + 1]) + COST * dp[mini + 1].Y){
			pos -= dod[++mini];
		}
		//printf("dp[ %d ] = %d %d\n", i, dp[i].X, dp[i].Y);
	}
	dp[mini].X += pos;
	return dp[mini];
}
 
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 < 45;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:70:7: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   70 |  scanf("%d%d%d", &n, &d, &L);
      |  ~~~~~^~~~~~~~~~~~~~~~~~~~~~
prison.cpp:73:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |   scanf("%d", tme + i);
      |   ~~~~~^~~~~~~~~~~~~~~

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