PAT 1053 Path of Equal Weight DFS

#include<cstdio>#include<iostream>#include<cstring>#include<algorithm>#include<vector>using namespace std;int a[105],fa[105];vector<int>v[105];int s;bool cmp(int x,int y){  return a[x]>a[y];}void out(int u){  vector<int>tp;  while(u)  {      tp.push_back(u);    u = fa[u];    }  cout<<a[0]<<" ";  for(int i = tp.size()-1;i>0;i--)cout<<a[tp[i]]<<" ";  if(tp.size())cout<<a[tp[0]]<<endl;}void dfs(int u,int w){  if(w+a[u] == s&&v[u].size() == 0)  {      out(u);    return;      }  if(w+a[u]>s)return;  for(int i = 0;i<v[u].size();i++)  {    int t = v[u][i];    dfs(t,w+a[u]);  }}int main(){  int n,m,i,j;  scanf("%d%d%d",&n,&m,&s);  memset(fa,-1,sizeof(fa));  for(i = 0;i<n;i++)  {    scanf("%d",&a[i]);  }  if(n == 1)  {    cout<<a[0]<<endl;    return 0;  }  for(i = 1;i<=m;i++)  {    int u,t,nm;    scanf("%d%d",&u,&nm);    for(j = 1;j<=nm;j++)    {      scanf("%d",&t);      v[u].push_back(t);      fa[t] = u;    }    sort(v[u].begin(),v[u].end(),cmp);  }  dfs(0,0);  return 0;}