例题6-7 树的层次遍历 BFS遍历

来源：互联网发布：雨田开版软件编辑：程序博客网时间：2024/06/05 18:52

题目链接：https://uva.onlinejudge.org/index.php?option=com_onlinejudge&Itemid=8&page=show_problem&category=&problem=58&mosmsg=Submission+received+with+ID+20135244

思路：根据输入的点建树，如果有重复赋值的则输出not complete ，然后就是用BFS遍历，把值存入vector容器，如果哪个节点没有值就输出not complete。

Code：

（指针实现）（AC）

#include <iostream>#include <cstdio>#include <vector>#include <queue>#include <string.h>#include <string>using namespace std;const int AX = 256;char s[AX << 2];vector<int>res ;bool flag;struct Node{bool have_value;Node *l , *r;int val;Node():have_value(false),l(NULL),r(NULL){}};Node* root;Node* newNode(){ return new Node(); }/*void remove_tree(Node* u){        //释放内存if( u == NULL ) return ;remove_tree(u->l);remove_tree(u->r);delete u;}*/void addNode( int v , char* s ){int len = strlen(s);Node* u = root ;for( int i = 0 ; i < len ; i++ ){if( s[i] == 'L' ){if( u -> l == NULL )  u -> l = newNode();u = u -> l;}else if( s[i] == 'R' ){if( u -> r == NULL )  u -> r = newNode();u = u -> r;}}if( u -> have_value )  flag = false ;  u -> val = v;u -> have_value = true;}bool input_node(){//remove_tree(root);root = newNode();flag = true;while(true){if( scanf("%s",s) != 1 ) return false;if( !strcmp(s,"()" )) return true;int v;sscanf(&s[1],"%d",&v);addNode( v , strchr(s,',') + 1 ) ;}}bool BFS(){queue <Node*> q;res.clear();q.push(root);while( !q.empty() ){Node* u = q.front(); q.pop();if( !u -> have_value ) return false;res.push_back(u -> val);if( u -> l != NULL ) q.push(u->l);if( u -> r != NULL ) q.push(u->r);}return true;}int main(){//freopen("openfile.txt","r",stdin);while(input_node()){if( !BFS() ) flag = false;if(flag){int len = res.size();for( int i = 0 ; i < len-1 ; i++ ){cout << res[i] << ' ';}cout << res[len-1] << endl;}else{ cout << "not complete" << endl;}}return 0;}

数组实现：（TE）数组比指针更慢，暂时不知道如何优化

#include <iostream>#include <cstdio>#include <vector>#include <queue>#include <string.h>#include <string>using namespace std;const int AX = 256;char s[AX << 2];const int root = 1;int left1[AX<<2], right1[AX<<2];bool have_value[AX<<2];int val[AX<<2];int cnt;vector<int>res ;bool flag;void newtree(){left1[root] = right1[root] = 0;have_value[root] = false;}int newNode(){int u = ++cnt;left1[u] = right1[u] = 0;have_value[u] = false;return u;}void addNode( int v , char* s ){int len = strlen(s);int u = root ;for( int i = 0 ; i < len ; i++ ){if( s[i] == 'L' ){if( left1[u] == 0 )  left1[u] = newNode();u = left1[u];}else if( s[i] == 'R' ){if( right1[u] == 0 ) right1[u] = newNode();u = right1[u];}}if( have_value[u] )  flag = false ;  val[u] = v;have_value[u] = true;}bool input_node(){cnt = 0;newtree();flag = true;while(true){if( scanf("%s",s) != 1 ) return false;if( !strcmp(s,"()" )) return true;int v;sscanf(&s[1],"%d",&v);addNode( v , strchr(s,',') + 1 ) ;}}bool BFS(){queue <int> q;res.clear();q.push(root);while( !q.empty() ){int u = q.front(); q.pop();if( !have_value[u] ) return false;res.push_back(val[u]);if( left1[u] != 0 ) q.push(left1[u]);if( right1[u] != 0 ) q.push(right1[u]);}return true;}int main(){//freopen("openfile.txt","r",stdin);while(input_node()){if( !BFS() ) flag = false;if(flag){int len = res.size();for( int i = 0 ; i < len-1 ; i++ ){cout << res[i] << ' ';}cout << res[len-1] << endl;}else{ cout << "not complete" << endl;}}return 0;}

阅读全文

0 0