oj.uz

Submission #920642

# Submission time Handle Problem Language Result Execution time Memory
920642 2024-02-02T20:06:17 Z alexander707070 Building 4 (JOI20_building4) C++14
11 / 100
 334 ms 195004 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 t=0;t<10;t++){

	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){
		for(int i=0;i<sol.size();i++){
			if(sol[i]=='A')cout<<1/0;
			if(sol[i]=='B' and p[i+1]!=b[i+1])cout<<1/0;
		}
		
		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:139:15: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  139 |  for(int i=0;i<sol.size();i++){
      |              ~^~~~~~~~~~~
building4.cpp:160:16: warning: comparison of integer expressions of different signedness: 'int' and 'std::__cxx11::basic_string<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  160 |   for(int i=0;i<sol.size();i++){
      |               ~^~~~~~~~~~~
building4.cpp:161:26: warning: division by zero [-Wdiv-by-zero]
  161 |    if(sol[i]=='A')cout<<1/0;
      |                         ~^~
building4.cpp:162:45: warning: division by zero [-Wdiv-by-zero]
  162 |    if(sol[i]=='B' and p[i+1]!=b[i+1])cout<<1/0;
      |                                            ~^~

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 8792 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 12892 KB Output is correct
7 Correct 3 ms 12892 KB Output is correct
8 Correct 3 ms 13148 KB Output is correct
9 Correct 3 ms 12892 KB Output is correct
10 Correct 3 ms 12892 KB Output is correct
11 Correct 4 ms 12892 KB Output is correct
12 Correct 3 ms 13148 KB Output is correct
13 Correct 3 ms 12892 KB Output is correct
14 Correct 3 ms 13144 KB Output is correct
15 Correct 3 ms 13148 KB Output is correct
16 Correct 3 ms 10844 KB Output is correct
17 Correct 4 ms 13144 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 13048 KB Output is correct
22 Correct 3 ms 13148 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 12888 KB Output is correct
26 Correct 3 ms 12892 KB Output is correct
27 Correct 3 ms 12892 KB Output is correct
28 Correct 2 ms 12896 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 13024 KB Output is correct
32 Correct 3 ms 12892 KB Output is correct
33 Correct 3 ms 13060 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 8792 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 12892 KB Output is correct
7 Correct 3 ms 12892 KB Output is correct
8 Correct 3 ms 13148 KB Output is correct
9 Correct 3 ms 12892 KB Output is correct
10 Correct 3 ms 12892 KB Output is correct
11 Correct 4 ms 12892 KB Output is correct
12 Correct 3 ms 13148 KB Output is correct
13 Correct 3 ms 12892 KB Output is correct
14 Correct 3 ms 13144 KB Output is correct
15 Correct 3 ms 13148 KB Output is correct
16 Correct 3 ms 10844 KB Output is correct
17 Correct 4 ms 13144 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 13048 KB Output is correct
22 Correct 3 ms 13148 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 12888 KB Output is correct
26 Correct 3 ms 12892 KB Output is correct
27 Correct 3 ms 12892 KB Output is correct
28 Correct 2 ms 12896 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 13024 KB Output is correct
32 Correct 3 ms 12892 KB Output is correct
33 Correct 3 ms 13060 KB Output is correct
34 Correct 148 ms 32828 KB Output is correct
35 Correct 304 ms 110768 KB Output is correct
36 Correct 307 ms 109360 KB Output is correct
37 Correct 312 ms 111052 KB Output is correct
38 Correct 276 ms 129996 KB Output is correct
39 Correct 269 ms 120252 KB Output is correct
40 Correct 289 ms 120556 KB Output is correct
41 Correct 295 ms 112308 KB Output is correct
42 Correct 318 ms 114352 KB Output is correct
43 Correct 330 ms 117576 KB Output is correct
44 Correct 334 ms 117456 KB Output is correct
45 Correct 326 ms 117728 KB Output is correct
46 Correct 295 ms 138236 KB Output is correct
47 Correct 298 ms 127052 KB Output is correct
48 Correct 288 ms 126824 KB Output is correct
49 Correct 295 ms 127020 KB Output is correct
50 Correct 322 ms 116556 KB Output is correct
51 Correct 323 ms 116548 KB Output is correct
52 Correct 276 ms 105648 KB Output is correct
53 Correct 275 ms 106056 KB Output is correct
54 Correct 242 ms 118448 KB Output is correct
55 Correct 238 ms 118596 KB Output is correct
56 Correct 304 ms 98292 KB Output is correct
57 Correct 260 ms 98124 KB Output is correct
58 Correct 255 ms 98232 KB Output is correct
59 Correct 253 ms 98296 KB Output is correct
60 Correct 222 ms 93824 KB Output is correct
61 Correct 238 ms 98296 KB Output is correct
62 Runtime error 318 ms 195004 KB Execution killed with signal 4
63 Halted 0 ms 0 KB -