Submission #1140755

#	Time	Username	Problem	Language	Result	Execution time	Memory
1140755		Sang	Miners (IOI07_miners)	C++20	100 / 100	57 ms	592 KiB

miners

#include<bits/stdc++.h>
using namespace std;

#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; i++)
#define FORD(i, a, b) for (int i = (a), _b = (b); i >= _b; i--)
#define fi first
#define se second
#define pb push_back
#define ALL(a) (a).begin(), (a).end()
#define task "kbsiudthw"

typedef vector<int> vi;
typedef pair<int, int> ii;
typedef pair<int, ii> pii;

const int N = 1e5 + 5;
const int INF = 0x3f3f3f3f;
const int MOD = 1e9 + 2277;

int n, c[N], dp[2][4][4][4][4];

int get(int a, int b, int c){
    int ans = (a != 3) + (b != 3) + 1;
    if (a != 3 && a == b) --ans;
    if (a == c) --ans;
    if (b != 3 && a != c && b == c) --ans;
    return ans;
}

signed main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    cin >> n;
    FOR (i, 1, n){
        char ch ; cin >> ch;
        c[i] = ch == 'B';
        if (ch == 'F') c[i] = 2;
    }
    FOR (i, 0, 1) FOR (c1, 0, 3) FOR (c2, 0, 3) FOR (c3, 0, 3) FOR (c4, 0, 3) dp[i][c1][c2][c3][c4] = -1e9;
    dp[0][3][3][3][3] = 0;
    int cur = 0;
    FOR (i, 1, n){
        cur ^= 1;
        FOR (c1, 0, 3) FOR (c2, 0, 3) FOR (c3, 0, 3) FOR (c4, 0, 3) dp[cur][c1][c2][c3][c4] = -1e9;
        FOR (c1, 0, 3) FOR (c2, 0, (int)max(c1, 2)) FOR (c3, 0, 3) FOR (c4, 0, (int)max(c3, 2)){
            dp[cur][c2][c[i]][c3][c4] = max(dp[cur][c2][c[i]][c3][c4], dp[cur^1][c1][c2][c3][c4] + get(c1, c2, c[i]));
            dp[cur][c1][c2][c4][c[i]] = max(dp[cur][c1][c2][c4][c[i]], dp[cur^1][c1][c2][c3][c4] + get(c3, c4, c[i]));
        }
    }
    int ans = 0;
    FOR (c1, 0, 3) FOR (c2, 0, 3) FOR(c3, 0, 3) FOR (c4, 0, 3) ans = max(ans, dp[cur][c1][c2][c3][c4]);
    cout << ans;

    return 0;
}

Compilation message (stderr)

miners.cpp: In function 'int main()':
miners.cpp:34:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   34 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
miners.cpp:35:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   35 |         freopen(task".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: 8 / 8
• Subtask 12: 8 / 8