Open cup #2

Posted 2020-10-01 Aragaki

A

D:用前面的H去消去后面的K 然后求最长连续的M

F:在每一列/行里面求最大的数然后组成最大的和ans[]里的比求出最大的

L:并查集

J:DP背锅题 01背包 先求出M种里每种的size和last然后先last最大的放在最后 然后背包DP

long long solve(Group* groups) {
    long long* x = new long long[n + 1];
    for (int i=0; i<n+1; i++) x[i] = INFINITY;
    x[0] = 0;

    // all groups but the last; the last always goes
    // into "last" bus
    for (int i=0; i<m-1; i++)
        for (int j=n-groups[i].size; j>=0; j--) {
            long long time = max(x[j], groups[i].time);
            x[j+groups[i].size] = min(time, x[j+groups[i].size]);
        }

    //for (int i=0; i<=n; i++) cout << x[i] << " ";
    //cout << endl;

    long long answer = -1;
    for (int i=0; i<=k; i++) 
        if (n - i <= k) if (x[i] < INFINITY) {
            long long total = x[i] * i + (n - i) * groups[m-1].time;
            if (answer == -1 || total < answer)
                answer = total;
        }
    
    return answer;
}

X[i]表示有i人在一个飞机上时的最小last

然后i从0枚举到k如果剩下的不大于K就统计total 更新答案