【层次遍历 P101】

来源：互联网发布：swift 网络请求第三方编辑：程序博客网时间：2024/06/05 06:22

#include<cstdio>#include<cstdlib>#include<cstring>const int MAXN=256;typedef struct TNode{int have_value;int v;struct TNode *left,*right;}Node ;Node *root;Node * newnode(){Node* u=(Node*)malloc(sizeof(Node));if(u!=NULL){u->have_value=0;u->left=u->right=NULL;}return u;}int failed;void addnode(int v,char *s){int n=strlen(s);Node *u=root;for(int i=0;i<n;i++)if(s[i]=='L'){if(u->left==NULL)u->left=newnode();u=u->left;}else if(s[i]=='R'){if(u->right==NULL)u->right=newnode();u=u->right;}if(u->have_value)failed=1;u->v=v;u->have_value=1;}void remove_tree(Node *u){if(u==NULL)return ;remove_tree(u->left);remove_tree(u->right);free(u);}char s[MAXN+10]; int read_input(){failed=0;remove_tree(root);root=newnode();for(;;){if(scanf("%s",s)!=1)return 0;      　　if(!strcmp(s,"()"))break;int v;sscanf(&s[1],"%d",&v);addnode(v,strchr(s,',')+1);}return 1;}int n=0,ans[MAXN];int bfs(){int front=0,rear=1;Node * q[MAXN];q[0]=root;while(front<rear){Node *u=q[front++];if(!u->have_value)return 0;ans[n++]=u->v;if(u->left!=NULL)q[rear++]=u->left;if(u->right!=NULL)q[rear++]=u->right;}return 1;}int main(){while(read_input()){if(!bfs())failed=1;if(failed)printf("-1\n");else{for(int i=0;i<n;i++)printf("%d ",ans[i]);printf("\n");}}}

程序解读：

char s[MAXN+10]; int read_input(){failed=0;remove_tree(root);root=newnode();for(;;){if(scanf("%s",s)!=1)return 0;      　　if(!strcmp(s,"()"))break;int v;sscanf(&s[1],"%d",&v);addnode(v,strchr(s,',')+1);}return 1;}