1004. Counting Leaves (30)

PAT 1004 用一个 BFS 搞定 哈哈

#include<iostream>

#include<cstdio>

#include<vector>

#include<queue>

using namespace std;

const int maxn=105;

const int INF=1000000000;

struct E{

    int from,to;

    E(int from,int to):

        from(from),to(to){}

    bool operator <(const E &rhs) const{

        return this->from<rhs.from;

    }

};

vector<E> edges;

vector<int> G[maxn];

int deep[maxn];

int deep_zero[maxn];

void init()

{

    for(int i=0;i<maxn;i++)

    {

        G[i].clear();

        deep[i]=INF;

        deep_zero[i]=0;

    }

    edges.clear();

    deep[1]=1;

}

void addEdge(int from,int to)

{

    edges.push_back(E(from,to));

    G[from].push_back(edges.size()-1);

}

int main()

{

#ifdef LOCAL

    freopen("data.in","r",stdin);

#endif

    int n,m,root,nums,child;

    init();

    scanf("%d%d",&n,&m);

    for(int j=1;j<=m;j++)

    {

    scanf("%d%d",&root,&nums);

    for(int i=1;i<=nums;i++)

    {

            scanf("%d",&child);

            addEdge(root,child);

    }

    }

    queue<int> nodes;

    nodes.push(1);

     deep[1]=1;

    int max_deep=1;

    while(!nodes.empty())

    {

        int from=nodes.front(); nodes.pop();

        for(int i=0;i<G[from].size();i++)

        {

            int to=edges[G[from][i]].to;

            deep[to]=deep[from]+1;

            nodes.push(to);

            if(deep[to]>max_deep)

                max_deep=deep[to];

        }

    }

    for(int i=1;i<=n;i++)

    {

        if(G[i].size()==0)

           deep_zero[deep[i]]+=1;

    }

    for(int i=1;i<=max_deep;i++)

    {

        cout<<deep_zero[i];

        if(i!=max_deep)

            cout<<" ";

    }

    cout<<endl;

    return 0;

}