Submission #589729

#	Time	Username	Problem	Language	Result	Execution time	Memory
589729		tranxuanbach	Miners (IOI07_miners)	C++17	100 / 100	396 ms	100812 KiB

miners

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
using namespace std;
using namespace __gnu_pbds;

#define endl '\n'
#define fi first
#define se second
#define For(i, l, r) for (auto i = (l); i < (r); i++)
#define ForE(i, l, r) for (auto i = (l); i <= (r); i++)
#define FordE(i, l, r) for (auto i = (l); i >= (r); i--)
#define Fora(v, a) for (auto v: (a))
#define bend(a) (a).begin(), (a).end()
#define isz(a) ((signed)(a).size())

using ll = long long;
using ld = long double;
using pii = pair <int, int>;
using vi = vector <int>;
using vpii = vector <pii>;
using vvi = vector <vi>;

const int N = 1e5 + 5, inf = 1e9 + 7;

int n;
string s;

int dp[N][4][4][4][4];

int f(char c){
    if (c == 'M'){
        return 1;
    }
    if (c == 'F'){
        return 2;
    }
    if (c == 'B'){
        return 3;
    }
    return 0;
}

int g(int i, int j, int k){
    int cnt[4] = {0, 0, 0, 0};
    cnt[i]++; cnt[j]++; cnt[k]++;
    return (cnt[1] ? 1 : 0) + (cnt[2] ? 1 : 0) + (cnt[3] ? 1 : 0);
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    // freopen("KEK.inp", "r", stdin);
    // freopen("KEK.out", "w", stdout);
    cin >> n;
    cin >> s;

    memset(dp, 0xc0, sizeof(dp));
    dp[0][0][0][0][0] = 0;
    For(i, 0, n){
        int ii = i & 1;
        ForE(m12, 0, 3){
            ForE(m11, 0, 3){
                ForE(m22, 0, 3){
                    ForE(m21, 0, 3){
                        dp[i + 1][m11][f(s[i])][m22][m21] = max(dp[i + 1][m11][f(s[i])][m22][m21], dp[i][m12][m11][m22][m21] + g(m12, m11, f(s[i])));
                        dp[i + 1][m12][m11][m21][f(s[i])] = max(dp[i + 1][m12][m11][m21][f(s[i])], dp[i][m12][m11][m22][m21] + g(m22, m21, f(s[i])));
                    }
                }
            }
        }
    }
    
    int ans = 0;
    ForE(m12, 0, 3){
        ForE(m11, 0, 3){
            ForE(m22, 0, 3){
                ForE(m21, 0, 3){
                    ans = max(ans, dp[n][m12][m11][m22][m21]);
                }
            }
        }
    }
    cout << ans << endl;
}

/*
==================================================+
INPUT:                                            |
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--------------------------------------------------|
==================================================+
OUTPUT:                                           |
--------------------------------------------------|

--------------------------------------------------|
==================================================+
*/

Compilation message (stderr)

miners.cpp: In function 'int main()':
miners.cpp:61:13: warning: unused variable 'ii' [-Wunused-variable]
   61 |         int ii = i & 1;
      |             ^~

• 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