树案例—列出叶结点

基础实验4-2.2 列出叶结点 (25分)

建树+层序遍历

运行结果

代码

#include <iostream>
#include <queue>
#include <cstring>
using namespace std;
#define NUL -1
typedef struct TreeNode *Node;
struct TreeNode{
    int data;
    int Left;
    int Right;
}s[50];
int flag=0;
queue<int>q;
void LevelSearch(int Tree){
    q.push(Tree);
    int temp;
    while (!q.empty()){
        temp=q.front();
        if(s[temp].Left==NUL&&s[temp].Right==NUL){//没有左右子节点即为叶节点
            if(flag)
                cout<<' ';
            cout<<temp;
            flag=1;
        }
        if(s[temp].Left!=NUL)
            q.push(s[temp].Left);
        if(s[temp].Right!=NUL)
            q.push(s[temp].Right);
        q.pop();
    }
}
int  main()
{
    int n;
    cin>>n;
    char a,b;
    int mark[n];
    memset(mark,0,sizeof(mark));
    for(int i=0;i<n;i++){
        s[i].Left=-1;
        s[i].Right=-1;
    }
    int Root;
    for (int i=0;i<n;i++){
        s[i].data=i;
        cin>>a>>b;
        if(a!='-'){
            s[i].Left=a-'0';
            mark[a-'0']++;
        }
        if(b!='-'){
            s[i].Right=b-'0';
            mark[b-'0']++;
        }
    }
    for (int i = 0; i < n; ++i) {
        if(mark[i]==0)
            Root=i;
    }
    LevelSearch(Root);
    return 0;
}