二元樹遍曆與常見操作

 

#include <cstdio>#include <cstdlib>#include <stack>#include <queue>#include <list>using namespace std;struct btree{btree(char c):data(c),left(NULL),right(NULL){}char data;btree *left, *right;};void preOrder(btree* root){btree* ptr = root;stack<btree*> st;while(!st.empty() || ptr!=NULL){if(ptr!=NULL){printf("%c\t", ptr->data);st.push(ptr);ptr = ptr->left;}else{ptr = st.top()->right;st.pop();}}}void midOrder(btree* root){btree* ptr = root;stack<btree*> st;while(!st.empty() || ptr!=NULL){if(ptr!=NULL){st.push(ptr);ptr = ptr->left;}else{printf("%c\t", st.top()->data);ptr = st.top()->right;st.pop();}}}void postOrder(btree* root){btree* ptr = root;stack<btree*> st;stack<bool> sflag;while(!st.empty() || ptr!=NULL){if(ptr!=NULL){st.push(ptr), sflag.push(false);ptr = ptr->left;}else if(sflag.top()==false){ptr = st.top()->right;sflag.top() = true;}else{printf("%c\t", st.top()->data);st.pop(), sflag.pop();}}}void levelOrder(btree* root){queue<btree*> q;q.push(root);while(!q.empty()){btree* ptr = q.front();q.pop();printf("%c\t", ptr->data);if(ptr->left!=NULL)q.push(ptr->left);if(ptr->right!=NULL)q.push(ptr->right);}}void maxDis(btree* root, int& h, int& dis, list<char>& listh, list<char>& listd){int lh, rh, ld, rd;list<char> listlh, listrh, listld, listrd;if(root!=NULL){maxDis(root->left,lh,ld,listlh,listld);maxDis(root->right,rh,rd,listrh,listrd);h = max(lh,rh) + 1;listh = lh>=rh? listlh : listrh;//to dump pathlisth.push_back(root->data);//to dump pathdis = max(max(ld,rd), rh+lh+2);/*to dump path*/if(ld >= rd && ld >= rh+lh+2)listd = listld;else if(rd >= ld && rd >= rh+lh+2)listd = listrd;else{listd = listlh;listd.push_back(root->data);for(list<char>::reverse_iterator it=listrh.rbegin();it!=listrh.rend();it++){listd.push_back(*it);}}}else{h = -1, dis = 0;}}void btreeMirror(btree* root){if(root!=NULL){btree* tmp = root->left;root->left = root->right;root->right = tmp;btreeMirror(root->left);btreeMirror(root->right);}}void btreeCopy(const btree* src, btree*& des){if(src==NULL){des = NULL;}else{des = new btree(src->data);btree *l, *r;btreeCopy(src->left, l);btreeCopy(src->right, r);des->left = l;des->right = r;}}bool btreeComp(const btree* src, btree* des){if(src==NULL && des!=NULL || src!=NULL && des==NULL)return false;else if(src==NULL && des==NULL)return true;else{if(src->data==des->data)return btreeComp(src->left,des->left) && btreeComp(src->right,des->right);elsereturn false;}}typedef void(*FUNC)(btree* root);int main(){FUNC func[] = {preOrder, midOrder, postOrder, levelOrder};int funcSize = sizeof(func)/sizeof(FUNC);const char* funcName[] = {"preOrder", "midOrder", "postOrder", "levelOrder"};btree a('a'),b('b'),c('c'),d('d'),e('e'),f('f'),g('g');a.left = &b, a.right = &c;b.left = &d, b.right = &e;e.left = &f, e.right = &g;btree* root = &a;for(int i=0;i<funcSize;i++){printf("%s:\t", funcName[i]);(*func[i])(root);printf("\n");}btree *copy;btreeCopy(&a,copy);if(btreeComp(&a,copy)){printf("tree copy:\t");preOrder(copy);printf("\n");}else{printf("something wrong!\n");exit(1);}btreeMirror(copy);printf("tree mirror:\t");preOrder(copy);printf("\n");int high, distance;list<char> lhigh, ldistance;maxDis(root,high, distance, lhigh, ldistance);printf("max distance:\t%d\npath:\t", distance);for(list<char>::iterator it=lhigh.begin();it!=lhigh.end();it++){printf("%c\t", *it);}printf("\n");printf("height:\t:%d\npath:\t", high);for(list<char>::iterator it=ldistance.begin();it!=ldistance.end();it++){printf("%c\t", *it);}printf("\n");return 0;}