Submission #1173813

#	Time	Username	Problem	Language	Result	Execution time	Memory
1173813		InvMOD	Miners (IOI07_miners)	C++20	84 / 100	1595 ms	584 KiB

miners

#include<bits/stdc++.h>

using namespace std;

#define sz(v) (int)(v).size()

template<typename T> bool ckmx(T& a, const T& b){
    if(a < b)
        return a = b, true;
    return false;
}

int n; string S;

namespace Sub1{

    void process()
    {
        auto calc = [&](string x) -> int{
            int answer = 0;
            for(int i = 0; i < sz(x); i++){
                if(i == 0){
                    answer = answer + 1;
                }
                else if(i == 1){
                    answer = answer + 1 + (x[i] != x[i - 1]);
                }
                else{
                    set<int> s = {x[i], x[i - 1], x[i - 2]};
                    answer = answer + sz(s);
                }
            }
            return answer;
        };

        int answer = 0;
        for(int mask = 0; mask < (1 << n); mask++){
            string mine1 = "", mine2 = "";
            for(int i = 0; i < n; i++){
                if(mask >> i & 1){
                    mine1 += S[i];
                }
                else mine2 += S[i];
            }

            answer = max(answer, calc(mine1) + calc(mine2));
        }

        cout << answer << "\n";
    }
}

/*
    We only care about 2 previous type

    dp[i][mine 1 first][mine 1 second][mine 2 first][mine 2 second]:

    at i, 2 previous type of mine 1, 2 previous type of mine 2

    if we did not choose, the type will be 0
*/

namespace Sub2{

    int dp[2][4][4][4][4];

    void process()
    {
        auto calc = [&](int first, int second, int cur) -> int{
            set<int> s = {first, second, cur};

            return sz(s) - (!((*s.begin())));
        };

        memset(dp[1], -0x3f, sizeof(dp[1]));
        dp[1][0][0][0][0] = 0;

        int answer = 0;
        for(int i = 0; i < n; i++){
            int type = (S[i] == 'M' ? 1 : (S[i] == 'F' ? 2 : 3));
            int cur = (i & 1), pre = (i & 1) ^ 1;

            memset(dp[cur], -0x3f, sizeof(dp[cur]));
            for(int m1t1 = 0; m1t1 <= 3; m1t1++){
                for(int m1t2 = 0; m1t2 <= 3; m1t2++){
                    for(int m2t1 = 0; m2t1 <= 3; m2t1++){
                        for(int m2t2 = 0; m2t2 <= 3; m2t2++){
                            ckmx(dp[cur][m1t2][type][m2t1][m2t2], dp[pre][m1t1][m1t2][m2t1][m2t2] + calc(m1t1, m1t2, type));
                            ckmx(dp[cur][m1t1][m1t2][m2t2][type], dp[pre][m1t1][m1t2][m2t1][m2t2] + calc(m2t1, m2t2, type));
                            ckmx(answer, dp[cur][m1t2][type][m2t1][m2t2]);
                            ckmx(answer, dp[cur][m1t1][m1t2][m2t2][type]);
                        }
                    }
                }
            }
        }

        cout << answer << "\n";
    }
}

void solve()
{
    cin >> n >> S;

    Sub2::process();
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);

    #define name "InvMOD"
    if(fopen(name".INP", "r")){
        freopen(name".INP", "r", stdin);
        freopen(name".OUT", "w", stdout);
    }

    solve();
    return 0;
}

Compilation message (stderr)

miners.cpp: In function 'int32_t main()':
miners.cpp:115:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  115 |         freopen(name".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
miners.cpp:116:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  116 |         freopen(name".OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• 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: 0 / 8
• Subtask 12: 0 / 8