分类:
2009-06-15 12:54:24
Time Limit:1s | Memory limit:32M |
Accepted Submit:64 | Total Submit:99 |
n boxes are placed on the vertices of a rooted tree, which are numbered
from 1 to n, 1 ≤ n ≤ 10000. Each box is either empty or contains a
number of marbles; the total number of marbles is n. The task is to
move the marbles such that each box contains exactly one marble. This
is to be accomplished be a sequence of moves; each move consists of
moving one marble to a box at an adjacent vertex. What is the minimum
number of moves required to achieve the goal?
Input
The input contains a number of cases. Each case starts with the number n followed by n lines. Each line contains at least three numbers which are: v the number of a vertex, followed by the number of marbles originally placed at vertex v followed by a number d which is the number of children of v, followed by d numbers giving the identities of the children of v.Output
For each case in the input, output the smallest number of moves of marbles resulting in one marble at each vertex of the tree.Sample input
9
1 2 3 2 3 4
2 1 0
3 0 2 5 6
4 1 3 7 8 9
5 3 0
6 0 0
7 0 0
8 2 0
9 0 0
9
1 0 3 2 3 4
2 0 0
3 0 2 5 6
4 9 3 7 8 9
5 0 0
6 0 0
7 0 0
8 0 0
9 0 0
9
1 0 3 2 3 4
2 9 0
3 0 2 5 6
4 0 3 7 8 9
5 0 0
6 0 0
7 0 0
8 0 0
9 0 0
0
Output for sample input
7
14
20
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