Submission #672523

#	Time	Username	Problem	Language	Result	Execution time	Memory
672523		sudheerays123	Miners (IOI07_miners)	C++17	91 / 100	1572 ms	244540 KiB

miners

#include<bits/stdc++.h>
using namespace std;
#define fast ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define ll long long int
const ll N = 1e5+5 , INF = 1e18 , MOD = 1e9+7;

ll dp[N][4][4][4][4];
vector<ll> a(N);
ll n;

ll chartoll(char x){
	if(x == 'M') return 1ll;
	if(x == 'B') return 2ll;
	return 3ll;
}

ll go(ll i , ll pre1 , ll pree1 , ll pre2 , ll pree2){

	if(i == n+1) return 0;
	if(dp[i][pre1][pree1][pre2][pree2] != -1) return dp[i][pre1][pree1][pre2][pree2];
	
	set<ll> s1;
	if(pre1 != 0) s1.insert(pre1);
	if(pree1 != 0) s1.insert(pree1);
	s1.insert(a[i]);
	ll uuu = s1.size();

	ll ans = uuu+go(i+1,a[i],pre1,pre2,pree2);
	
	set<ll> s2;
	if(pre2 != 0) s2.insert(pre2);
	if(pree2 != 0) s2.insert(pree2);
	s2.insert(a[i]);
	ll uu = s2.size();

	ans = max(ans,uu+go(i+1,pre1,pree1,a[i],pre2));
	
	return dp[i][pre1][pree1][pre2][pree2] = ans;
}

void solve(){

	string s;
	cin >> n >> s;
	s = ' '+s;
	for(ll i = 1; i <= n; i++) a[i] = chartoll(s[i]);

	if(n <= 20){

		ll ans = -INF;

		for(ll i = 0; i < (1ll<<n); i++){

			vector<char> mine1,mine2;
			for(ll j = 0; j < n; j++){
				if(i&(1ll<<j)) mine1.push_back(s[j+1]);
				else mine2.push_back(s[j+1]);
			}

			ll score = 0;

			for(ll j = 0; j < mine1.size(); j++){
				set<char> food;
				for(ll k = j; k >= max(0ll,j-2); k--) food.insert(mine1[k]);
				score += food.size();
			}

			for(ll j = 0; j < mine2.size(); j++){
				set<char> food;
				food.insert(mine2[j]);
				for(ll k = j; k >= max(0ll,j-2); k--) food.insert(mine2[k]);
				score += food.size();
			}

			ans = max(ans,score);
		}

		// cout << ans;
		// return;
	}

	memset(dp,-1,sizeof dp);

	cout << go(1,0,0,0,0);
}

int main(){

	fast;

	ll tc = 1;
	// cin >> tc;
	while(tc--) solve();

	return 0;
}

Compilation message (stderr)

miners.cpp: In function 'void solve()':
miners.cpp:62:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   62 |    for(ll j = 0; j < mine1.size(); j++){
      |                  ~~^~~~~~~~~~~~~~
miners.cpp:68:20: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<char>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   68 |    for(ll j = 0; j < mine2.size(); j++){
      |                  ~~^~~~~~~~~~~~~~

• Subtask 1: 9 / 9
• Subtask 2: 9 / 9
• Subtask 3: 9 / 9
• Subtask 4: 9 / 9
• Subtask 5: 0 / 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