Submission #643590

#	Time	Username	Problem	Language	Result	Execution time	Memory
643590		Cyber_Wolf	Miners (IOI07_miners)	C++14	100 / 100	998 ms	242944 KiB

miners

// Problem: P4 - Miners
// Contest: DMOJ - IOI '07
// URL: https://dmoj.ca/problem/ioi07p4
// Memory Limit: 16 MB
// Time Limit: 750 ms
// 
// Powered by CP Editor (https://cpeditor.org)

 
#include <bits/stdc++.h>
 
using namespace std;
 
#define lg long long
#define fastio ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

const lg N = 1e5+5;

lg dp[N][256];
lg n;
string s;
vector<lg> v(N);
 
lg solve(lg idx, lg bit)
{
	if(idx == n)
	{
		return 0;
	}
	auto &ret = dp[idx][bit];
	if(~ret)	return ret;
	lg x = ((bit/64)&3), y = ((bit/16)&3), a = ((bit/4)&3), b = (bit&3);
	set<lg> se1;
	if(v[idx] != 3)	se1.insert(v[idx]);
	if(x != 3)	se1.insert(x);
	if(y != 3)	se1.insert(y);
	set<lg> se2;
	if(v[idx] != 3)	se2.insert(v[idx]);
	if(a != 3)	se2.insert(a);
	if(b != 3)	se2.insert(b);
	lg ch1 = solve(idx+1, v[idx]*64+x*16+a*4+b)+se1.size();
	lg ch2 = solve(idx+1, x*64+y*16+v[idx]*4+a)+se2.size();
	return ret = max(ch1, ch2);
}
 
int main()
{
	fastio;
	cin >> n >> s;
	for(int i = 0; i < n; i++)
	{
		if(s[i] == 'M')	v[i] = 1;
		if(s[i] == 'B')	v[i] = 2;
		for(int j = 0; j < 256; j++)
		{
			dp[i][j] = -1;
		}
	}
	cout << solve(0, 3*64+3*16+3*4+3) << '\n';
	
    return 0;
}

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 9 / 9
• Subtask 6: 7 / 7
• Subtask 7: 8 / 8
• Subtask 8: 8 / 8
• Subtask 9: 8 / 8
• Subtask 10: 8 / 8
• Subtask 11: 8 / 8
• Subtask 12: 8 / 8