oj.uz

Submission #920630

# Submission time Handle Problem Language Result Execution time Memory
920630 2024-02-02T19:55:24 Z alexander707070 Building 4 (JOI20_building4) C++14
11 / 100
 298 ms 102480 KB 
#include<bits/stdc++.h>
#define MAXN 1000007
using namespace std;

const int inf=1e9;

int n,a[MAXN],b[MAXN],cnt,p[MAXN],l,r;
int dp[MAXN][2],dp2[MAXN][2];
bool li[MAXN][2],li2[MAXN][2];

queue<int> s;

string sol,sol2;

int ff(int pos,int last){
	if(pos==n+1)return 0;

	if(li[pos][last])return dp[pos][last];
	li[pos][last]=true;
	dp[pos][last]=-inf;

	int x=0;
	if(last==0)x=a[pos-1];
	else x=b[pos-1];

	if(a[pos]>=x){
		dp[pos][last]=max(dp[pos][last],ff(pos+1,0)+1);
	}

	if(b[pos]>=x){
		dp[pos][last]=max(dp[pos][last],ff(pos+1,1));
	}

	return dp[pos][last];
}

int ff2(int pos,int last){
	if(pos==n+1)return 0;

	if(li2[pos][last])return dp2[pos][last];
	li2[pos][last]=true;
	dp2[pos][last]=-inf;

	int x=0;
	if(last==0)x=a[pos-1];
	else x=b[pos-1];

	if(a[pos]>=x){
		dp2[pos][last]=max(dp2[pos][last],ff2(pos+1,0));
	}

	if(b[pos]>=x){
		dp2[pos][last]=max(dp2[pos][last],ff2(pos+1,1)+1);
	}

	return dp2[pos][last];
}

void solve(int pos,int last){
	if(pos==n+1)return;

	int x;
	if(last==0)x=a[pos-1];
	else x=b[pos-1];

	if(a[pos]>=x and ff(pos,last)==ff(pos+1,0)+1){
		sol+="A"; solve(pos+1,0); return;
	}else{
		sol+="B"; solve(pos+1,1); return;
	}
}

void solve2(int pos,int last){
	if(pos==n+1)return;

	int x;
	if(last==0)x=a[pos-1];
	else x=b[pos-1];

	if(b[pos]>=x and ff2(pos,last)==ff2(pos+1,1)+1){
		sol2+="B"; solve2(pos+1,1); return;
	}else{
		sol2+="A"; solve2(pos+1,0); return;
	}
}

bool vis[MAXN];

void bfs(int pos){

	if(pos>0 and !vis[pos-1] and sol[pos-1]=='A' and sol2[pos-1]=='B'){
		l=pos-1;
		if(b[l+1]>=p[l] and b[l+1]<=p[l+2]){
			s.push(pos-1);
			vis[pos-1]=true;
		}
	}

	if(pos<n-1 and !vis[pos+1] and sol[pos+1]=='A' and sol2[pos+1]=='B'){
		l=pos+1;
		if(b[l+1]>=p[l] and b[l+1]<=p[l+2]){
			s.push(pos+1);
			vis[pos+1]=true;
		}
	}
}

int main(){

	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	cin>>n;
	n*=2;
	for(int i=1;i<=n;i++){
		cin>>a[i];
	}
	for(int i=1;i<=n;i++){
		cin>>b[i];
	}

	if(ff(1,0)<0 or ff(1,0)<n/2 or ff2(1,0)<n/2){
		cout<<"-1\n";
		return 0;
	}

	cnt=ff(1,0);
	solve(1,0); solve2(1,0);

	for(int i=0;i<sol.size();i++){
		if(sol[i]=='A')p[i+1]=a[i+1];
		else p[i+1]=b[i+1];
	}
	p[n+1]=inf;

	for(int i=0;i<sol.size();i++){
		if(sol[i]=='A' and sol2[i]=='B'){
			if(b[i+1]>=p[i] and b[i+1]<=p[i+2]){
				s.push(i); vis[i]=true;
			}
		}
	}

	while(cnt>n/2 and !s.empty()){
		sol[s.front()]='B'; 
		p[s.front()+1]=b[s.front()+1];

		bfs(s.front());
		s.pop();

		cnt--;
	}

	if(cnt>n/2){
		cout<<"-1\n";
		return 0;
	}

	cout<<sol<<"\n";
	

	return 0;
}

Compilation message

building4.cpp: In function 'int main()':
building4.cpp:131:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  131 |  for(int i=0;i<sol.size();i++){
      |              ~^~~~~~~~~~~
building4.cpp:137:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  137 |  for(int i=0;i<sol.size();i++){
      |              ~^~~~~~~~~~~

Subtask #1
11.0 / 11.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 12632 KB Output is correct
2 Correct 1 ms 8540 KB Output is correct
3 Correct 2 ms 12636 KB Output is correct
4 Correct 2 ms 12636 KB Output is correct
5 Correct 2 ms 8540 KB Output is correct
6 Correct 3 ms 13016 KB Output is correct
7 Correct 2 ms 12892 KB Output is correct
8 Correct 3 ms 13144 KB Output is correct
9 Correct 2 ms 12892 KB Output is correct
10 Correct 2 ms 12892 KB Output is correct
11 Correct 3 ms 12892 KB Output is correct
12 Correct 3 ms 13144 KB Output is correct
13 Correct 3 ms 12892 KB Output is correct
14 Correct 3 ms 12888 KB Output is correct
15 Correct 3 ms 12888 KB Output is correct
16 Correct 3 ms 10840 KB Output is correct
17 Correct 3 ms 12892 KB Output is correct
18 Correct 3 ms 12892 KB Output is correct
19 Correct 3 ms 12892 KB Output is correct
20 Correct 3 ms 12892 KB Output is correct
21 Correct 3 ms 12892 KB Output is correct
22 Correct 3 ms 12892 KB Output is correct
23 Correct 3 ms 12892 KB Output is correct
24 Correct 3 ms 12892 KB Output is correct
25 Correct 3 ms 12892 KB Output is correct
26 Correct 2 ms 13012 KB Output is correct
27 Correct 3 ms 12892 KB Output is correct
28 Correct 2 ms 12892 KB Output is correct
29 Correct 3 ms 12892 KB Output is correct
30 Correct 3 ms 12892 KB Output is correct
31 Correct 3 ms 12892 KB Output is correct
32 Correct 3 ms 12892 KB Output is correct
33 Correct 3 ms 12888 KB Output is correct

Subtask #2
0 / 89.0

# Verdict Execution time Memory Grader output
1 Correct 2 ms 12632 KB Output is correct
2 Correct 1 ms 8540 KB Output is correct
3 Correct 2 ms 12636 KB Output is correct
4 Correct 2 ms 12636 KB Output is correct
5 Correct 2 ms 8540 KB Output is correct
6 Correct 3 ms 13016 KB Output is correct
7 Correct 2 ms 12892 KB Output is correct
8 Correct 3 ms 13144 KB Output is correct
9 Correct 2 ms 12892 KB Output is correct
10 Correct 2 ms 12892 KB Output is correct
11 Correct 3 ms 12892 KB Output is correct
12 Correct 3 ms 13144 KB Output is correct
13 Correct 3 ms 12892 KB Output is correct
14 Correct 3 ms 12888 KB Output is correct
15 Correct 3 ms 12888 KB Output is correct
16 Correct 3 ms 10840 KB Output is correct
17 Correct 3 ms 12892 KB Output is correct
18 Correct 3 ms 12892 KB Output is correct
19 Correct 3 ms 12892 KB Output is correct
20 Correct 3 ms 12892 KB Output is correct
21 Correct 3 ms 12892 KB Output is correct
22 Correct 3 ms 12892 KB Output is correct
23 Correct 3 ms 12892 KB Output is correct
24 Correct 3 ms 12892 KB Output is correct
25 Correct 3 ms 12892 KB Output is correct
26 Correct 2 ms 13012 KB Output is correct
27 Correct 3 ms 12892 KB Output is correct
28 Correct 2 ms 12892 KB Output is correct
29 Correct 3 ms 12892 KB Output is correct
30 Correct 3 ms 12892 KB Output is correct
31 Correct 3 ms 12892 KB Output is correct
32 Correct 3 ms 12892 KB Output is correct
33 Correct 3 ms 12888 KB Output is correct
34 Correct 141 ms 14016 KB Output is correct
35 Correct 253 ms 92876 KB Output is correct
36 Correct 251 ms 91596 KB Output is correct
37 Correct 254 ms 93180 KB Output is correct
38 Correct 252 ms 96832 KB Output is correct
39 Correct 244 ms 94424 KB Output is correct
40 Correct 267 ms 98940 KB Output is correct
41 Correct 276 ms 94676 KB Output is correct
42 Correct 259 ms 95956 KB Output is correct
43 Correct 270 ms 98304 KB Output is correct
44 Correct 274 ms 98232 KB Output is correct
45 Correct 272 ms 98124 KB Output is correct
46 Correct 268 ms 102480 KB Output is correct
47 Correct 257 ms 99312 KB Output is correct
48 Correct 257 ms 99148 KB Output is correct
49 Correct 282 ms 99664 KB Output is correct
50 Correct 270 ms 98124 KB Output is correct
51 Correct 270 ms 98296 KB Output is correct
52 Correct 228 ms 98768 KB Output is correct
53 Correct 225 ms 98348 KB Output is correct
54 Correct 227 ms 102396 KB Output is correct
55 Correct 208 ms 101196 KB Output is correct
56 Correct 298 ms 98460 KB Output is correct
57 Correct 255 ms 97972 KB Output is correct
58 Correct 251 ms 98240 KB Output is correct
59 Correct 250 ms 98296 KB Output is correct
60 Correct 223 ms 93776 KB Output is correct
61 Correct 228 ms 98260 KB Output is correct
62 Incorrect 237 ms 96184 KB Output isn't correct
63 Halted 0 ms 0 KB -