中序和一个别的序可以确定一颗bst，而先序和后序不能！
1 #include <iostream> 2 #include <cstring> 3 #include <cstdio> 4 using namespace std; 5 6 const int N = 11; 7 char str[N]; 8 int cnt; 9 int arr1[N]; 10 int arr2[N]; 11 12 struct Node 13 { 14 Node * ch[2]; 15 int v; 16 bool cmp( int x ) 17 { 18 if ( x == v ) return -1; 19 return x < v ? 0 : 1; 20 } 21 }; 22 23 Node * root1, * root2; 24 25 void insert( Node * & o, int x ) 26 { 27 if ( o == NULL ) 28 { 29 o = new Node (); 30 o->ch[0] = o->ch[1] = NULL; 31 o->v = x; 32 return ; 33 } 34 int d = o->cmp(x); 35 if ( d == -1 ) return ; 36 insert( o->ch[d], x ); 37 } 38 39 void free( Node * o ) 40 { 41 if ( o != NULL ) 42 { 43 free(o->ch[0]); 44 free(o->ch[1]); 45 delete o; 46 } 47 } 48 49 void preorder( Node * o, int * arr ) 50 { 51 if ( o ) 52 { 53 arr[cnt++] = o->v; 54 preorder( o->ch[0], arr ); 55 preorder( o->ch[1], arr ); 56 } 57 } 58 59 void inorder( Node * o, int * arr ) 60 { 61 if ( o ) 62 { 63 inorder( o->ch[0], arr ); 64 arr[cnt++] = o->v; 65 inorder( o->ch[1], arr ); 66 } 67 } 68 69 bool judge( Node * r1, Node * r2 ) 70 { 71 cnt = 0; 72 preorder( r1, arr1 ); 73 cnt = 0; 74 preorder( r2, arr2 ); 75 for ( int i = 0; i < cnt; i++ ) 76 { 77 if ( arr1[i] != arr2[i] ) return false; 78 } 79 cnt = 0; 80 inorder( r1, arr1 ); 81 cnt = 0; 82 inorder( r2, arr2 ); 83 for ( int i = 0; i < cnt; i++ ) 84 { 85 if ( arr1[i] != arr2[i] ) return false; 86 } 87 return true; 88 } 89 90 int main () 91 { 92 int n; 93 while ( scanf("%d", &n), n ) 94 { 95 root1 = NULL; 96 scanf("%s", str); 97 for ( int i = 0; i < strlen(str); i++ ) 98 { 99 insert( root1, str[i] ); 100 } 101 for ( int i = 0; i < n; i++ ) 102 { 103 root2 = NULL; 104 scanf("%s", str); 105 for ( int i = 0; i < strlen(str); i++ ) 106 { 107 insert( root2, str[i] ); 108 } 109 if ( judge( root1, root2 ) ) 110 { 111 printf("YES "); 112 } 113 else 114 { 115 printf("NO "); 116 } 117 free(root2); 118 } 119 free(root1); 120 } 121 return 0; 122 }