Submission #643732

#	Time	Username	Problem	Language	Result	Execution time	Memory
643732		Cyber_Wolf	Miners (IOI07_miners)	C++14	100 / 100	344 ms	852 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 int
#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);
// }
lg dp[2][N];

lg calc(lg a, lg b, lg c)
{
	lg ans = 0;
	for(int i = 0; i < 3; i++)
	{
		if(a == 0 || b == 0 || c == 0)	ans++;		
		a--, b--, c--;
	}
	return ans;
}
 
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 i = n-1; i >= 0; i--)
	{
		for(int j = 0; j < 256; j++)
		{
			lg x = ((j>>6)&3), y = ((j>>4)&3), a = ((j>>2)&3), b = (j&3);
			dp[i&1][j] = max(dp[!(i&1)][v[i]*64+x*16+a*4+b]+calc(v[i], x, y), dp[!(i&1)][x*64+y*16+v[i]*4+a]+calc(v[i], a, b));
		}
	}
	cout << dp[0][255] << '\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