PAT：1053. Path of Equal Weight (30) AC

#include<stdio.h>
#include<vector>
#include<queue>
#include<algorithm>
using namespace std;
const int MAX=1010;

int n,m;        //n个节点，m个非叶子节点
long long int S;    //待测权值

long long int weight[MAX];  //每个节点的权值

vector<int> child[MAX];    //存储节点

bool cmp(int a,int b)
{
  return weight[a]>weight[b];
}

long long int sum=0;
vector<int> path;  //存路径权值
void DFS(int root)
{
  if(child[root].size()==0)
  {
    if(sum==S)
    {
      printf("%d",path.front());    //权值S不为0，符合条件一定有路径。单独输出首个，控制后面空格数
      for(int i=1 ; i<path.size() ; ++i)
        printf(" %d",path[i]);    //输出剩余路径
      printf("\n");
    }
    return;
  }
  for(int i=0 ; i<child[root].size() ; ++i)
  {
    sum+=weight[child[root][i]];    //加上该孩子的权值
    //printf("root=%d, i=%d, sum=%lld, child[root][i]=%d\n", root, i, sum, child[root][i]);
    path.push_back(weight[child[root][i]]);    //该孩子加入到路径
    DFS(child[root][i]);
    sum-=path[path.size()-1];
    path.pop_back();
  }
}
int main()
{
  scanf("%d%d%lld",&n,&m,&S);
  for(int i=0 ; i<n ; ++i)
    scanf("%lld",&weight[i]);
  for(int i=0 ; i<m ; ++i)
  {
    int father,k,c;
    scanf("%d%d",&father,&k);
    for(int j=0 ; j<k ; ++j)
    {
      scanf("%d",&c);
      child[father].push_back(c);
    }
    sort(child[father].begin(),child[father].end(),cmp);    //【skill】对vector进行排序，保证遍历的时候从大到小
  }
  path.push_back(weight[0]);
  sum+=weight[0];
  DFS(0);
  return 0;
}