1102. Invert a Binary Tree (25)

1102. Invert a Binary Tree (25)
2017.9.9更新

#include <iostream>
#include <vector>
#include <queue>
#include <algorithm>
using namespace std;
struct TreeNode
{
    int left,right;
    TreeNode(int L=-1,int R=-1):left(L),right(R){}
};
bool root[10];
int n,cnt;
vector<TreeNode> tree;
void invert(int r)
{
    if(r!=-1)
    {
        swap(tree[r].left,tree[r].right);
        invert(tree[r].left);
        invert(tree[r].right);
    }
}
void levtra(int r)
{
    queue<int> q;
    q.push(r);
    while(!q.empty())
    {
        int s=q.front();
        ++cnt!=n?cout<<s<<" ":cout<<s<<endl;
        q.pop();
        if(tree[s].left!=-1)q.push(tree[s].left);
        if(tree[s].right!=-1)q.push(tree[s].right);
    }
}
void inotra(int r)
{
    if(r!=-1)
    {
        inotra(tree[r].left);
        ++cnt!=n?cout<<r<<" ":cout<<r<<endl;
        inotra(tree[r].right);
    }
}
int main()
{
    cin>>n;
    tree.reserve(n);
    for(int i=0;i<n;++i)
    {
        char lc,rc;
        cin>>lc>>rc;
        if(lc!='-') root[tree[i].left=lc-'0']=1;
        else tree[i].left=-1;
        if(rc!='-') root[tree[i].right=rc-'0']=1;
        else tree[i].right=-1;
    }
    int r=0;
    while(root[r])++r;
    invert(r);
    levtra(r);
    cnt=0;
    inotra(r);
    return 0;
}

以前的ac代码

#include <stdio.h>
struct tree//树节点
{
    int left,right;
}node[12];
int findroot[12];
int main()
{
    int n,i;
    scanf("%d",&n);
    getchar();
    for(i=0;i<n;++i)
    {
        char l,r;
        scanf("%c %c",&l,&r);
        getchar();
        node[i].left=(l=='-')?-1:l-'0',findroot[l-'0']=1;
        node[i].right=(r=='-')?-1:r-'0',findroot[r-'0']=1;
    }
    while(i>=0&&findroot[--i]);//找根
    int root=i;
    int queue[100],front=0,rear=0,s;
    queue[rear++]=root;
    while(front<rear)//层序遍历
    {
        s=queue[front++];
        if(node[s].right!=-1)
            queue[rear++]=node[s].right;
        if(node[s].left!=-1)
            queue[rear++]=node[s].left;
        front==rear?printf("%d\n",s):printf("%d ",s);
    }
    int stack[100],top=0,c=0;
    s=root;
    while(s!=-1||top)//非递归中序遍历
    {
        while(s!=-1)
        {
            stack[top++]=s;
            s=node[s].right;
        }
        if(top)
        {
            s=stack[--top];
            ++c;
            c==n?printf("%d",s):printf("%d ",s);
            s=node[s].left;
        }
    }
    return 0;
}

转载于:https://www.cnblogs.com/xLester/p/7570379.html