[sicily online]1156. Binary tree(遞迴先序遍曆)

//用map來儲存圖//遞迴先序遍曆#include<iostream>#include<set>#include<vector>#include<map>using namespace std;typedef struct NODE{char value;int parent;int lchild;int rchild;//struct NODE():value('\0'),parent(0),lchild(0),rchild(0){}}Node;void pre(map<int,Node> &gra,int index){cout<<gra[index].value;if(gra[index].lchild!=0)pre(gra,gra[index].lchild);if(gra[index].rchild!=0)pre(gra,gra[index].rchild);}int main(){int n;while(cin>>n){map<int,Node>gra;for(int i=0;i<n;i++){int index;cin>>index;cin>>gra[index].value>>gra[index].lchild>>gra[index].rchild;gra[gra[index].lchild].parent=index;gra[gra[index].rchild].parent=index;}map<int,Node>::iterator ite;int tmpIndex=0;for(ite=gra.begin();ite!=gra.end();ite++){if(ite->second.parent==0){tmpIndex=ite->first;break;}}pre(gra,tmpIndex);cout<<endl;}//end while}