1064 Complete Binary Search Tree
阿新 • • 發佈：2019-02-11
#include<bits/stdc++.h> using namespace std; const int MAXN=100010; struct Node{ int data; Node* left; Node* right; Node(){ left=NULL; right=NULL; } }node[MAXN]; vector<int> in,le,pre; Node* build(int l,int r){ Node* root=new Node; int num=r-l+1;int level=0; level=(int)(log(num*1.0)/log(2.0))+1; int numleft,numright; if(level==1) numleft=0; else{ if(3*pow(2.0,level-2)-1>=num){ numright = pow(2.0,level-2)-1; numleft = num-1-numright; } else{ numleft = pow(2.0,level-1)-1; numright = num-1-numleft; } } root->data=in[l+numleft]; if(numleft==0){ root->left=NULL; }else{ root->left=build(l,l+numleft-1); } if(num-numleft-1==0){ root->right=NULL; }else{ root->right=build(r-numright+1,r); } return root; } void levetra(Node* root){ queue<Node*> q; q.push(root); while(!q.empty()){ Node* now=q.front(); q.pop(); le.push_back(now->data); if(now->left!=NULL) q.push(now->left); if(now->right!=NULL) q.push(now->right); } } int main() { #ifdef ONLINE_JUDGE #else freopen("in.txt","r",stdin); #endif int n;cin>>n;in.resize(n); for(int i=0;i<n;i++){ cin>>in[i]; } sort(in.begin(),in.end()); Node* root=build(0,n-1); levetra(root); for(int i=0;i<n;i++){ if(i==0) cout<<le[i]; else cout<<' '<<le[i]; } return 0; }
#include<bits/stdc++.h> using namespace std; const int MAXN=100010; struct Node{ int data; Node* left; Node* right; Node(){ data=-1; left=NULL; right=NULL; } }node[MAXN]; vector<int> in,le; Node* build(int l,int r){ if(l>r) return NULL; int num=r-l+1;int level=0; /*for(int i=1;i<num;i++){ if(num<=(pow(2,i)-1)&&num>(pow(2,i-1)-1)){ level=i;break; } }*/ level=log(num)/log(2)+1; int numleft; if(level==1){ numleft=0; }else{ int halflastlevelnum=pow(2,level-2); int lastlevelnum=num-(pow(2,level-1)-1); if(lastlevelnum<=halflastlevelnum) numleft=lastlevelnum+(pow(2,level-2)-1); else{ numleft=halflastlevelnum+(pow(2,level-2)-1); } } Node* root=new Node; root->data=in[l+numleft]; root->left=build(l,l+numleft-1); root->right=build(l+numleft+1,r); return root; } void levetra(Node* root){ queue<Node*> q; q.push(root); while(!q.empty()){ Node* now=q.front(); q.pop(); le.push_back(now->data); if(now->left!=NULL) q.push(now->left); if(now->right!=NULL) q.push(now->right); } } int main() { #ifdef ONLINE_JUDGE #else freopen("in.txt","r",stdin); #endif int n;cin>>n;in.resize(n); for(int i=0;i<n;i++){ cin>>in[i]; } sort(in.begin(),in.end()); Node* root=build(0,n-1); levetra(root); for(int i=0;i<n;i++){ if(i==0) cout<<le[i]; else cout<<' '<<le[i]; } return 0; }
兩段程式碼都能AC，有一個問題卡了半天，就是計算層數的時候本來想用for迴圈，結果總是有兩個節點的位置不太對，後來只能妥協用公式，可以AC了
#include<bits/stdc++.h> using namespace std; const int MAXN=100010; struct Node{ int data; Node* left; Node* right; Node(){ data=-1; left=NULL; right=NULL; } }node[MAXN]; vector<int> in,le; Node* build(int l,int r){ if(l>r) return NULL; int num=r-l+1;int level=0; /*for(int i=1;i<num;i++){ if(num<=pow(2,i)&&num>pow(2,i-1)){ level=i;break; } }*/ level=log(num)/log(2)+1; int numleft; int halflastlevelnum=pow(2,level-1)/2; int lastlevelnum=num-(pow(2,level-1)-1); if(lastlevelnum<=halflastlevelnum) numleft=lastlevelnum+(pow(2,level-1)-2)/2; else{ numleft=halflastlevelnum+(pow(2,level-1)-2)/2; } Node* root=new Node; root->data=in[l+numleft]; root->left=build(l,l+numleft-1); root->right=build(l+numleft+1,r); return root; } void levetra(Node* root){ queue<Node*> q; q.push(root); while(!q.empty()){ Node* now=q.front(); q.pop(); le.push_back(now->data); if(now->left!=NULL) q.push(now->left); if(now->right!=NULL) q.push(now->right); } } int main() { #ifdef ONLINE_JUDGE #else freopen("in.txt","r",stdin);freopen("out.txt","w",stdout); #endif int n;cin>>n;in.resize(n); for(int i=0;i<n;i++){ cin>>in[i]; } sort(in.begin(),in.end()); Node* root=build(0,n-1); levetra(root); for(int i=0;i<n;i++){ if(i==0) cout<<le[i]; else cout<<' '<<le[i]; } return 0; }