1 #include<stdio.h> 2 #include<stdlib.h> 3 4 typedef struct node 5 { 6 double w; 7 struct node *l,*r; 8 }*Node; 9 10 void Build(Node &rt,double a)//建树 11 { 12 if(rt==NULL) 13 { 14 rt=new node; 15 rt->w=a; 16 rt->l=0; 17 rt->r=0; 18 } 19 else 20 { 21 if(a<rt->w) 22 Build(rt->l,a); 23 else 24 Build(rt->r,a); 25 } 26 } 27 double fin(struct node *rt) //找最小的权 28 { 29 if(!rt) 30 return 0; 31 else if(!rt->l) 32 return rt->w; 33 else 34 return fin(rt->l); 35 } 36 37 void delet(Node &rt,double w)//删除权为w点 38 { 39 if(!rt) 40 { 41 printf("没有 "); 42 return ; 43 } 44 else if(rt->w<w) 45 delet(rt->r,w); 46 else if(rt->w>w) 47 delet(rt->l,w); 48 else if(rt->l&&rt->r) 49 { 50 struct node *tmp; 51 tmp=rt; 52 tmp->w=fin(tmp->r); 53 delet(tmp->r,tmp->w); 54 } 55 else 56 { 57 struct node *t; 58 t=rt; 59 if(rt->l) 60 rt=rt->l; 61 else 62 rt=rt->r; 63 delete(t); 64 } 65 66 } 67 void in(struct node *rt) //中序 68 { 69 if(rt) 70 { 71 in(rt->l); 72 printf("%lf ",rt->w); 73 in(rt->r); 74 } 75 else 76 return ; 77 } 78 double w; 79 int aim; 80 81 void search(Node rt,int &cnt) //找第aim小 82 { 83 if(rt) 84 { 85 search(rt->l,cnt); 86 cnt++; 87 if(cnt==aim) 88 { 89 w=rt->w; 90 return; 91 } 92 search(rt->r,cnt); 93 94 } 95 } 96 int main() 97 { 98 int n; 99 scanf("%d",&n); 100 struct node *root; 101 root=0; 102 for(int i=1;i<=n;i++) //插入 103 { 104 double a; 105 scanf("%lf",&a); 106 Build(root,a); 107 } 108 in(root); 109 printf(" "); 110 scanf("%d",&n); 111 for(int i=1;i<=n;i++) //删除 112 { 113 double a; 114 scanf("%lf",&a); 115 delet(root,a); 116 in(root); 117 printf(" "); 118 } 119 scanf("%d",&n); 120 for(int i=1;i<=n;i++) 121 { 122 scanf("%d",&aim); //第aim小 123 int cnt=0; 124 search(root,cnt); 125 printf("%lf ",w); 126 } 127 return 0; 128 } 129 /* 130 9 131 3 4 2 5 7 6 3.5 3.1 3.6 132 0 133 3 134 6 135 7 136 3 137 138 */