Submission #733914

#	Time	Username	Problem	Language	Result	Execution time	Memory
733914		myrcella	The short shank; Redemption (BOI21_prison)	C++17	0 / 100	13 ms	25684 KiB

prison

//by szh
#include<bits/stdc++.h>
using namespace std;

#define fi first
#define se second
#define pii pair<int,int>
#define pll pair<long long,long long>
#define pb push_back
#define debug(x) cerr<<#x<<"="<<x<<endl
#define pq priority_queue
#define inf 0x3f
#define rep(i,a,b) for (int i=a;i<(b);i++)
#define MP make_pair
#define SZ(x) (int(x.size()))
#define ll long long
#define mod 1000000007
#define ALL(x) x.begin(),x.end()
void inc(int &a,int b) {a=(a+b)%mod;}
void dec(int &a,int b) {a=(a-b+mod)%mod;}
int lowbit(int x) {return x&(-x);}
ll p0w(ll base,ll p) {ll ret=1;while(p>0){if (p%2ll==1ll) ret=ret*base%mod;base=base*base%mod;p/=2ll;}return ret;}

const int maxn = 8e4;
int n,d,T;
int t[maxn];
int le[maxn];
int mn[maxn][21];
int lg[maxn];

int query(int l,int r) {
	int tmp = lg[r-l+1];
	return min(mn[l][tmp],mn[r-(1<<tmp)+1][tmp]);
}

int tree[maxn*4][20],add[maxn*4][20];

void update(int id,int c,int cl,int cr,int l,int r,int val) {
	if (l<=cl and cr<=r) {
		tree[c][id] += val;
		add[c][id] += val;
		return;
	}
	int mid=cl+cr>>1;
	if (add[c][id]!=0) {
		tree[c<<1][id] += add[c][id];
		tree[c<<1|1][id] += add[c][id];
		add[c<<1][id] += add[c][id];
		add[c<<1|1][id] += add[c][id];
		add[c][id] = 0;
	}
	if (l<=mid) update(id,c<<1,cl,mid,l,r,val);
	if (r>mid) update(id,c<<1|1,mid+1,cr,l,r,val);
	tree[c][id] = max(tree[c<<1][id],tree[c<<1|1][id]);
	return;
}

int main() {
//	freopen("input.txt","r",stdin);	
	std::ios::sync_with_stdio(false);cin.tie(0);
	cin>>n>>d>>T;
	rep(i,0,n) cin>>t[i],mn[i][0] = t[i]-i;
	lg[1] = 0;
	rep(i,2,maxn) lg[i] = lg[i/2]+1;
	for (int i = n-1;i>=0;i--) 
		rep(j,1,21) {
			if (i+(1<<j)>n) break;
			mn[i][j] = min(mn[i][j-1],mn[i+(1<<(j-1))][j-1]);
		}
	rep(i,0,n) {
		if (t[i]<=T) le[i] = maxn;
		else {
			int l = 0,r=i;
			while (l<r) {
				int mid = l+r>>1;
				if (mid==i or query(mid,i-1)+i>T) r=mid;
				else l = mid+1;
			}
			le[i] = l;
		}
	}
	memset(tree,0,sizeof(tree));
	int ans = 0;
	if (le[0]==0) update(0,1,0,n-1,0,0,1);
	rep(i,1,n) {
		for (int j = d;j>0;j--) update(j,1,0,n-1,i,i,tree[1][j-1]);
		if (le[i]<=i) rep(j,0,d+1) update(j,1,0,n-1,le[i],i,1);
	}
	cout<<n-tree[1][d];
	return 0;
}

Compilation message (stderr)

prison.cpp: In function 'void update(int, int, int, int, int, int, int)':
prison.cpp:44:12: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   44 |  int mid=cl+cr>>1;
      |          ~~^~~
prison.cpp: In function 'int main()':
prison.cpp:75:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   75 |     int mid = l+r>>1;
      |               ~^~
prison.cpp:83:6: warning: unused variable 'ans' [-Wunused-variable]
   83 |  int ans = 0;
      |      ^~~

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