Submission #414637

#	Time	Username	Problem	Language	Result	Execution time	Memory
414637		DavidDamian	Miners (IOI07_miners)	C++11	100 / 100	239 ms	110248 KiB

miners

#include <bits/stdc++.h>

using namespace std;
///Dynamic Programming
///Determine the maximum amount of coal
int n;
int food[100005];
int memo[100005][4][4][4][4];
int different(int a, int b, int c) ///Returns the quantity of different types of food
{
    if (a > b) swap(a, b);
    if (b > c) swap(b, c);
    if (a > b) swap(a, b);
    int cnt = 1;
    if (a != b) {
        cnt++;
    }
    if (b != c) {
        cnt++;
    }
    if (a == 0) cnt--; // a = 0 means no food
    return cnt;
}

///State: actual index of food, two last from mine 1, two last from mine 2
int coal(int i, int X1, int X2, int Y1, int Y2)
{
    if (i == n) return 0;
    if (memo[i][X1][X2][Y1][Y2] == -1) {
        int maximum = max(coal(i + 1, food[i], X1, Y1, Y2)
                          + different(food[i], X1, X2), ///Send food to mine 1
                          coal(i + 1, X1, X2, food[i], Y1)
                          + different(food[i], Y1, Y2)); ///Send food to mine 2
        memo[i][X1][X2][Y1][Y2] = maximum;
    }
    return memo[i][X1][X2][Y1][Y2];
}
int main()
{
    memset(memo, -1, sizeof(memo));
    cin >> n;
    for (int i = 0; i < n; i++) {
        char c;
        cin >> c;
        if (c == 'M')
            food[i] = 1;
        else if (c == 'F')
            food[i] = 2;
        else if (c == 'B')
            food[i] = 3;
    }
    int maximum = coal(0, 0, 0, 0, 0);
    cout << maximum << '\n';
    return 0;
}

• 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