1053. Path of Equal Weight (30)

Given a non-empty tree with root R, and with weight Wi assigned to each tree node Ti. 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 Figure 1: 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 Figure 1.



Figure 1Input Specification:
Each input file contains one test case. Each case starts with a line containing 0 < N <= 100, the number of nodes in a tree, M (< N), the number of non-leaf nodes, and 0 < S < 230, the given weight number. The next line contains N positive numbers where Wi (<1000) corresponds to the tree node Ti. 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 {A1, A2, ..., An} is said to be greater than sequence {B1, B2, ..., Bm} if there exists 1 <= k < min{n, m} such that Ai = Bi for i=1, ... k, and Ak+1 > Bk+1.
Sample Input:

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:

10 5 2 7
10 4 10
10 3 3 6 2
10 3 3 6 2

题目大意：

代码：#include<stdio.h>
#include<vector>
#include<map>
#include<algorithm>
using namespace std;
struct node
{
int index;
int weight;
};
map<int,vector<struct node> > Map;
int weight[101];
int sum,n,m,k;
vector<int> path;
bool cmp(struct node a,struct node b)
{
return a.weight>b.weight;
}
void DFS(int root)
{
if(sum<k)
{
sort(Map[root].begin(),Map[root].end(),cmp);
for(int i=0;i<Map[root].size();i++)
{
sum+=Map[root][i].weight;
path.push_back(Map[root][i].index);
DFS(Map[root][i].index);
sum-=Map[root][i].weight;
path.pop_back();
}
}
else if(sum==k&&Map[root].size()==0)
{
for(int i=0;i<path.size();i++)
{
if(i==0)
{
printf("%d",weight[path[i]]);
}
else
{
printf(" %d",weight[path[i]]);
}
}
printf("\n");
}
}
int main()
{
int i,j,t,index,l;
scanf("%d %d %d",&n,&m,&k);
for(i=0;i<n;i++)
{
scanf("%d",&weight[i]);
}
for(i=0;i<m;i++)
{
scanf("%d",&index);
scanf("%d",&l);
for(j=0;j<l;j++)
{
scanf("%d",&t);
struct node tmp;
tmp.index=t;
tmp.weight=weight[t];
Map[index].push_back(tmp);
}
}
sum=weight[0];
path.push_back(0);
DFS(0);
return 0;
}