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PROGRAMMING:Path of Equal Weight

Luz5年前 (2021-05-10)题库532
Given a non-empty tree with root $$R$$, and with weight $$W_ i$$ assigned to each tree node $$T_ i$$. The **weight of a path from $$R$$ to $$L$$** is defined to be the sum of the weights of all the nodes along the path from $$R$$ to any leaf node $$L$$.
Now given any weighted tree, you are supposed to find all the paths with their weights equal to a given number. For example, let's consider the tree showed in the following figure: for each node, the upper number is the node ID which is a two-digit number, and the lower number is the weight of that node. Suppose that the given number is 24, then there exists 4 different paths which have the same given weight: {10 5 2 7}, {10 4 10}, {10 3 3 6 2} and {10 3 3 6 2}, which correspond to the red edges in the figure.
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### Input Specification:
Each input file contains one test case. Each case starts with a line containing $$0 < N \le 100$$, the number of nodes in a tree, $$M$$ ($$< N$$), the number of non-leaf nodes, and $$0 < S < 2^{30}$$, the given weight number. The next line contains $$N$$ positive numbers where $$W_ i$$ ($$<1000$$) corresponds to the tree node $$T_ i$$. Then $$M$$ lines follow, each in the format:
```
ID K ID[1] ID[2] ... ID[K]
```
where `ID` is a two-digit number representing a given non-leaf node, `K` is the number of its children, followed by a sequence of two-digit `ID`'s of its children. For the sake of simplicity, let us fix the root ID to be `00`.
### Output Specification:
For each test case, print all the paths with weight S in **non-increasing** order. Each path occupies a line with printed weights from the root to the leaf in order. All the numbers must be separated by a space with no extra space at the end of the line.
Note: sequence $$\{A_ 1, A_ 2, \cdots , A_ n\}$$ is said to be **greater than** sequence $$\{B_ 1, B_ 2, \cdots , B_ m\}$$ if there exists $$1 \le k < min\{n, m\}$$ such that $$A_ i = B_ i$$ for $$i=1, \cdots , k$$, and $$A_{ k+1} > B_{ k+1}$$.
### Sample Input:
```in
20 9 24
10 2 4 3 5 10 2 18 9 7 2 2 1 3 12 1 8 6 2 2
00 4 01 02 03 04
02 1 05
04 2 06 07
03 3 11 12 13
06 1 09
07 2 08 10
16 1 15
13 3 14 16 17
17 2 18 19
```
### Sample Output:
```out
10 5 2 7
10 4 10
10 3 3 6 2
10 3 3 6 2
```
### Special thanks to Zhang Yuan and Yang Han for their contribution to the judge's data.






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