Submission #154559

#	Time	Username	Problem	Language	Result	Execution time	Memory
154559		liwi	Rectangles (IOI19_rect)	C++14	72 / 100	5123 ms	931144 KiB

rect

#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("sse4,popcnt,abm,mmx,tune=native")

#include <bits/stdc++.h>

//using namespace std;

#define INT_INF 0x3f3f3f3f
#define mp std::make_pair

#define MAXN 2501

typedef long long ll;
typedef std::pair<int,int> pii;

int num_rows,num_cols,arr[MAXN][MAXN],bit[MAXN],cnt[MAXN][MAXN],ans,l,r,lst[MAXN],pp;
std::vector<pii> row_dp[MAXN][MAXN],col_dp[MAXN][MAXN];
pii dq[MAXN];

inline void update(int i, int val, int curr){
	for(; i<=num_cols; i+=i&-i){
		if(lst[i] != curr) bit[i] = val, lst[i] = curr;
		else bit[i]+=val;
	}
}

inline int query(int i, int curr){
	int res = 0;
	for(; i>0; i-=i&-i)
		if(lst[i] == curr)
			res+=bit[i];
	return res;
}

inline void init_rows(){
//	memset(cnt,0,sizeof cnt);
	for(int i=2; i<num_rows; i++){
		l = 1, r = 0;
		for(int k=1; k<=num_cols; k++){
			while(r-l+1 > 0 && dq[r].first < arr[i][k]) r--;
			int lft = (r-l+1>0?dq[r].second:INT_INF);
			if(lft < k-1 && (row_dp[lft+1][k-1].empty() || row_dp[lft+1][k-1].back().first != i))
				row_dp[lft+1][k-1].emplace_back(i,i), cnt[lft+1][k-1]++; //rows[i].pb(mp(lft+1,k-1));
			while(r-l+1 > 0 && dq[r].first == arr[i][k]) r--;
			dq[++r] = mp(arr[i][k],k);
		}
		l = 1, r = 0;
		for(int k=num_cols; k>=1; k--){
			while(r-l+1 > 0 && dq[r].first < arr[i][k]) r--;
			int rgt = (r-l+1>0?dq[r].second:-INT_INF);
			if(rgt > k+1 && (row_dp[k+1][rgt-1].empty() || row_dp[k+1][rgt-1].back().first != i))
				row_dp[k+1][rgt-1].emplace_back(i,i), cnt[k+1][rgt-1]++; //rows[i].pb(mp(k+1,rgt-1));
			while(r-l+1 > 0 && dq[r].first == arr[i][k]) r--;
			dq[++r] = mp(arr[i][k],k);
		}
	}
}

inline void init_cols(){
	memset(cnt,0,sizeof cnt);
	for(int i=2; i<num_cols; i++){
		l = 1, r = 0;
		for(int k=1; k<=num_rows; k++){
			while(r-l+1 > 0 && dq[r].first < arr[k][i]) r--;
			int lft = (r-l+1>0?dq[r].second:INT_INF);
			if(lft < k-1 && (col_dp[lft+1][k-1].empty() || col_dp[lft+1][k-1].back().first != i))
				col_dp[lft+1][k-1].emplace_back(i,i), cnt[lft+1][k-1]++; //cols[i].pb(mp(lft+1,k-1));
			while(r-l+1 > 0 && dq[r].first == arr[k][i]) r--;
			dq[++r] = mp(arr[k][i],k);
		}
		l = 1, r = 0;
		for(int k=num_rows; k>=1; k--){
			while(r-l+1 > 0 && dq[r].first < arr[k][i]) r--;
			int rgt = (r-l+1>0?dq[r].second:-INT_INF);
			if(rgt > k+1 && (col_dp[k+1][rgt-1].empty() || col_dp[k+1][rgt-1].back().first != i))
				col_dp[k+1][rgt-1].emplace_back(i,i), cnt[k+1][rgt-1]++; //cols[i].pb(mp(k+1,rgt-1));
			while(r-l+1 > 0 && dq[r].first == arr[k][i]) r--;
			dq[++r] = mp(arr[k][i],k);
		}
	}
}

inline void calc_hor_dp(){
//	for(int i=2; i<num_rows; i++){
//		sort(all(rows[i])); complete_unique(rows[i]);
//		for(pii check:rows[i]){
//			h_segs[check.first][check.second].pb(i);
////			r_range[i][check.first].pb(check.second);
//		}
//		rows[i].clear();
//	}
	std::vector<std::pair<pii,int>> dep[MAXN];
	for(int l=2; l<=num_cols-1; l++){
		for(int r=l; r<=num_cols-1; r++){
			if(cnt[l][r] == 0) continue;
			std::vector<pii> &nums = row_dp[l][r];
//			sort(all(nums)); complete_unique(nums);
//			std::vector<pii> t;
			int lst = 0;
			for(int i=1; i<cnt[l][r]; i++){
				if(nums[i].first == nums[i-1].first+1) continue;
				for(int k=nums[lst].first; k<=nums[i-1].first; k++)
					dep[nums[i-1].first-k+1].emplace_back(mp(k,l),r);
//					row_dp[k][l].pb(mp(nums[i-1].first-k+1,r));
				lst = i;
			}
			for(int k=nums[lst].first; k<=nums[cnt[l][r]-1].first; k++)
				dep[nums[cnt[l][r]-1].first-k+1].emplace_back(mp(k,l),r);
//				row_dp[k][l].pb(mp(nums[cnt[l][r]-1].first-k+1,r));
			nums.clear();
		}
	}
	for(int i=1; i<=num_rows; i++){
		for(auto &check:dep[i])
			row_dp[check.first.first][check.first.second].emplace_back(i,check.second);
	}
//	for(int l=2; l<=num_cols-1; l++){
//		for(int r=l; r<=num_cols-1; r++){
//			reverse(all(row_dp[l][r]));
//			while(cnt[l][r]--) row_dp[l][r].pop_back();
//			reverse(all(row_dp[l][r]));
//		}
//	}
}

inline void calc_col_dp(){
//	for(int i=2; i<num_cols; i++){
//		sort(all(cols[i])); complete_unique(cols[i]);
//		for(pii check:cols[i]){
//			v_segs[check.first][check.second].pb(i);
////			v_range[check.first][i].pb(check.second);
//		}
//		cols[i].clear();
//	}
	for(int l=2; l<=num_rows-1; l++){
		for(int r=l; r<=num_rows-1; r++){
			if(cnt[l][r] == 0) continue;
			std::vector<pii> &nums = col_dp[l][r];
//			sort(all(nums)); complete_unique(nums);
			int lst = 0;
			for(int i=1; i<cnt[l][r]; i++){
				if(nums[i].first == nums[i-1].first+1) continue;
				for(int k=nums[lst].first; k<=nums[i-1].first; k++)
					col_dp[l][k].emplace_back(r,nums[i-1].first);
				lst = i;
			}
			for(int k=nums[lst].first; k<=nums[cnt[l][r]-1].first; k++)
				col_dp[l][k].emplace_back(r,nums[cnt[l][r]-1].first);
		}
	}
//	for(int l=2; l<=num_cols-1; l++){
//		for(int r=l; r<=num_cols-1; r++){
//			reverse(all(col_dp[l][r]));
//			while(cnt[l][r]--) col_dp[l][r].pop_back();
//			reverse(all(col_dp[l][r]));
//		}
//	}
}

ll count_rectangles(std::vector<std::vector<int>> a){
	ans = 0, num_rows = (int)a.size(), num_cols = (int)a[0].size();
	for(int i=0; i<a.size(); i++)
		for(int k=0; k<a[i].size(); k++)
			arr[i+1][k+1] = a[i][k];
	init_rows(); calc_hor_dp();
	init_cols(); calc_col_dp();
	for(int i=num_rows-1; i>=2; i--){
		for(int k=num_cols-1; k>=2; k--){
//			sort(all(row_dp[i][k]));
//			sort(all(col_dp[i][k]));
			int ptr = cnt[i][k], res = 0, cc = 0; ++pp;
			for(int v=0; v<row_dp[i][k].size(); v++){
//				pii curr = row_dp[i][k][v];
				while(ptr < col_dp[i][k].size() && col_dp[i][k][ptr].first-i+1 <= row_dp[i][k][v].first){
//					assert(col_dp[i][k][ptr].second>=k);
					update(col_dp[i][k][ptr].second-k+1,1,pp);
					ptr++, cc++;
				}
				res+=cc-query(row_dp[i][k][v].second-k,pp);
			}
//			while(--ptr >= cnt[i][k]) update(col_dp[i][k][ptr].second-k+1,-1);
			ans+=res;
		}
	}
	return ans;
}

Compilation message (stderr)

rect.cpp: In function 'll count_rectangles(std::vector<std::vector<int> >)':
rect.cpp:163:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<a.size(); i++)
               ~^~~~~~~~~
rect.cpp:164:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int k=0; k<a[i].size(); k++)
                ~^~~~~~~~~~~~
rect.cpp:173:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for(int v=0; v<row_dp[i][k].size(); v++){
                 ~^~~~~~~~~~~~~~~~~~~~
rect.cpp:175:15: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
     while(ptr < col_dp[i][k].size() && col_dp[i][k][ptr].first-i+1 <= row_dp[i][k][v].first){
           ~~~~^~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 8 / 8
• Subtask 2: 7 / 7
• Subtask 3: 12 / 12
• Subtask 4: 22 / 22
• Subtask 5: 10 / 10
• Subtask 6: 13 / 13
• Subtask 7: 0 / 28