Submission #1151066

#	Time	Username	Problem	Language	Result	Execution time	Memory
1151066		btninh	Miners (IOI07_miners)	C++20	100 / 100	134 ms	201620 KiB

miners

#include <bits/stdc++.h>
using namespace std;
#define int long long
const int N = 100005;
const int mod = 1e9 + 7;

int n, a[N], dp[N][4][4][4][4];

int cost(int a, int b, int c){
    int cnt = 1;
    if (a != b && b != 0) ++cnt;
    if (a != c && b != c && b != 0 && c != 0) ++cnt;
    return cnt;
}

signed main(){
    //freopen("test.inp","r",stdin);
    //freopen("test.out","w",stdout);
    ios::sync_with_stdio(0); cin.tie(0);
    
    cin >> n;
    for(int i = 1; i <= n; ++i){
        char c; cin >> c;
        if (c == 'M') a[i] = 1;
        if (c == 'F') a[i] = 2;
        if (c == 'B') a[i] = 3;
    }
    for(int i = 0; i <= n; ++i)
        for(int j1 = 0; j1 <= 3; ++j1)
            for(int j2 = 0; j2 <= 3; ++j2)
                for(int k1 = 0; k1 <= 3; ++k1)
                    for(int k2 = 0; k2 <= 3; ++k2) dp[i][j1][j2][k1][k2] = -1e18;
    
    dp[1][0][0][0][0] = 0;
    int ans = 0;
    for(int i = 1; i <= n + 1; ++i){
        for(int j1 = 0; j1 <= 3; ++j1){
            for(int j2 = 0; j2 <= 3; ++j2){
                for(int k1 = 0; k1 <= 3; ++k1){
                    for(int k2 = 0; k2 <= 3; ++k2){
                        if (dp[i][j1][j2][k1][k2] != -1e18) 
                        {
                            ans = max(ans, dp[i][j1][j2][k1][k2]);
                            dp[i + 1][a[i]][j1][k1][k2] = max(dp[i + 1][a[i]][j1][k1][k2], dp[i][j1][j2][k1][k2] + cost(a[i], j1, j2));
                            dp[i + 1][j1][j2][a[i]][k1] = max(dp[i + 1][j1][j2][a[i]][k1], dp[i][j1][j2][k1][k2] + cost(a[i], k1, k2));
                        }
                    }
                }
            }
        }
    }
    cout << ans;
}

• 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