Submission #1038335

#	Time	Username	Problem	Language	Result	Execution time	Memory
1038335		Dan4Life	Comparing Plants (IOI20_plants)	C++17	100 / 100	1852 ms	81488 KiB

plants

#include "plants.h"
#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define sz(a) (int)a.size()
#define all(a) begin(a), end(a)
using ar2 = array<int,2>;
const int mxN = (int)2e5+10;
const int mxLg = (int)19;
const int INF = (int)1e9;
int n, k, h[mxN*2];
int jmp[2][mxLg][mxN*2];

template<class T, int SZ> struct SegTree{
	T seg[SZ], lzy[SZ];
	
	void init(){ fill(seg,seg+SZ,0), fill(lzy,lzy+SZ,0); }
	
	void prop(int p, int l, int r){
		if(!lzy[p] or l==r) return;
		int mid = (l+r)/2; int rp = p+2*(mid-l+1);
		seg[p+1]+=lzy[p];
		seg[rp]+=lzy[p];
		lzy[p+1]+=lzy[p];
		lzy[rp]+=lzy[p];
		lzy[p]=0;
	}
	
	void upd(int i, int j, int v, int p=0, int l=0, int r=n-1){
		if(i>r or j<l or i>j) return; prop(p,l,r);
		if(i<=l and r<=j){ seg[p]+=v; lzy[p]+=v; return; }
		int mid = (l+r)/2; int rp = p+2*(mid-l+1);
		if(i<=mid) upd(i,j,v,p+1,l,mid);
		if(j>mid) upd(i,j,v,rp,mid+1,r);
		seg[p] = min(seg[p+1],seg[rp]);
	}
	
	int findFirstMin(int i, int j, int p=0, int l=0, int r=n-1){
		if(i>r or j<l or i>j) return -1; prop(p,l,r);
		if(l==r) return l; 
		int mid = (l+r)/2; int rp = p+2*(mid-l+1);
		if(i>mid) return findFirstMin(i,j,rp,mid+1,r);
		if(j<=mid) return findFirstMin(i,j,p+1,l,mid);
		if(query(i,mid)==query(i,j)) return findFirstMin(i,j,p+1,l,mid);
		return findFirstMin(i,j,rp,mid+1,r);
	}
	
	T query(int i, int j, int p=0, int l=0, int r=n-1){
		if(j<l or i>r or i>j) return INF; prop(p,l,r);
		if(i<=l and r<=j) return seg[p];
		int mid = (l+r)/2; int rp = p+2*(mid-l+1);
		return min(query(i,j,p+1,l,mid), query(i,j,rp,mid+1,r)); 
	}
};
const int mxSeg = 2*mxN;
SegTree<int,mxSeg> segTree;

int cur;
void solve(int i){
	bool ok = 1;
	while(ok){
		ok = 0;
		if(i<k){
			int i1 = segTree.findFirstMin(n-k+i,n-1);
			if(i1!=-1 and !segTree.query(i1,i1)) solve(i1), ok=1;
		}
		int i1 = segTree.findFirstMin(max(0,i-k),i-1);
		if(i1!=-1 and !segTree.query(i1,i1)) solve(i1), ok=1;
	}
	if(i<k){
		segTree.upd(0,i-1,-1);
		segTree.upd(n-k+i,n-1,-1);
	}
	else segTree.upd(i-k,i-1,-1);
	segTree.upd(i,i,INF); h[i]=cur--;
}

void init(int K, vector<int> r){
	n = sz(r); k=K-1; cur = n; 
	memset(jmp,-1, sizeof jmp);
	segTree.init(); 
	for(int i = 0; i < n; i++) 
		segTree.upd(i,i,r[i]);
	while(!segTree.query(0,n-1)) 
		solve(segTree.findFirstMin(0,n-1));
	for(int i = n; i < 2*n; i++) h[i] = h[i-n];
	set<ar2> S; int j = 0;
	for(int i = 0; i < 2*n; i++){
		while(j<2*n and abs(i-j)<=k)
			S.insert({h[j],j}),j++;
		S.erase({h[i],i});
		auto itr = S.lower_bound({h[i],i});
		if(itr!=end(S)) jmp[0][0][i]=(*itr)[1];
		if(itr!=begin(S)) jmp[1][0][i]=(*prev(itr))[1];
	}
	for(int t = 0; t < 2; t++)
		for(int i = 1; i < mxLg; i++)
			for(int j = 0; j < 2*n; j++)
				if(jmp[t][i-1][j]!=-1) jmp[t][i][j]
					=jmp[t][i-1][jmp[t][i-1][j]];
}

int comp(int x, int y, bool g){
	for(int i = mxLg-1; i>=0; i--){
		int j = jmp[g][i][x];
		if(j!=-1 and j<=y) x=j;
	}
	return y-x<=k and (g?h[x]>=h[y]:h[x]<=h[y]);
}

int compare_plants(int x, int y){
	if(comp(x,y,1) or comp(y,x+n,0)) return 1;
	if(comp(x,y,0) or comp(y,x+n,1)) return -1;
	return 0;
}

Compilation message (stderr)

plants.cpp: In member function 'void SegTree<T, SZ>::upd(int, int, int, int, int, int)':
plants.cpp:30:3: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   30 |   if(i>r or j<l or i>j) return; prop(p,l,r);
      |   ^~
plants.cpp:30:33: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   30 |   if(i>r or j<l or i>j) return; prop(p,l,r);
      |                                 ^~~~
plants.cpp: In member function 'int SegTree<T, SZ>::findFirstMin(int, int, int, int, int)':
plants.cpp:39:3: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   39 |   if(i>r or j<l or i>j) return -1; prop(p,l,r);
      |   ^~
plants.cpp:39:36: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   39 |   if(i>r or j<l or i>j) return -1; prop(p,l,r);
      |                                    ^~~~
plants.cpp: In member function 'T SegTree<T, SZ>::query(int, int, int, int, int)':
plants.cpp:49:3: warning: this 'if' clause does not guard... [-Wmisleading-indentation]
   49 |   if(j<l or i>r or i>j) return INF; prop(p,l,r);
      |   ^~
plants.cpp:49:37: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'if'
   49 |   if(j<l or i>r or i>j) return INF; prop(p,l,r);
      |                                     ^~~~

• Subtask 1: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 13 / 13
• Subtask 4: 17 / 17
• Subtask 5: 11 / 11
• Subtask 6: 15 / 15
• Subtask 7: 25 / 25