5-12 树种统计 (25分)

随着卫星成像技术的应用，自然资源研究机构可以识别每一棵树的种类。请编写程序帮助研究人员统计每种树的数量，计算每种树占总数的百分比。

输入格式:

输入首先给出正整数N（\le 10^5≤10

​5

​​ ），随后N行，每行给出卫星观测到的一棵树的种类名称。种类名称由不超过30个英文字母和空格组成（大小写不区分）。

输出格式:

按字典序递增输出各种树的种类名称及其所占总数的百分比，其间以空格分隔，保留小数点后4位。

输入样例:

29

Red Alder

Ash

Aspen

Basswood

Ash

Beech

Yellow Birch

Ash

Cherry

Cottonwood

Ash

Cypress

Red Elm

Gum

Hackberry

White Oak

Hickory

Pecan

Hard Maple

White Oak

Soft Maple

Red Oak

Red Oak

White Oak

Poplan

Sassafras

Sycamore

Black Walnut

Willow

输出样例:

Ash 13.7931%

Aspen 3.4483%

Basswood 3.4483%

Beech 3.4483%

Black Walnut 3.4483%

Cherry 3.4483%

Cottonwood 3.4483%

Cypress 3.4483%

Gum 3.4483%

Hackberry 3.4483%

Hard Maple 3.4483%

Hickory 3.4483%

Pecan 3.4483%

Poplan 3.4483%

Red Alder 3.4483%

Red Elm 3.4483%

Red Oak 6.8966%

Sassafras 3.4483%

Soft Maple 3.4483%

Sycamore 3.4483%

White Oak 10.3448%

Willow 3.4483%

Yellow Birch 3.4483%

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
typedef struct Node *BTree;
struct Node{
char Data[30];
double Rate;
BTree Left;
BTree Right;
};
void InstorderTraversal(BTree BT,int N);
BTree Insert(BTree BT,char *X);
int main(){
BTree BT;
BT=NULL;
int i,N;
char X[30];
scanf("%d",&N);
getchar();
for(i=0;i<N;i++){
gets(X);
BT=Insert(BT,X);
}
InstorderTraversal(BT,N);
return 0;
}

BTree Insert(BTree BT,char *X){
if(!BT){
BT=(BTree)malloc(sizeof(struct Node));
strcpy(BT->Data,X);
BT->Rate=1;
BT->Left=NULL;
BT->Right=NULL;
return BT;
}
if(strcmp(BT->Data,X)>0){
//    printf("!%s***\n",X);
BT->Left=Insert(BT->Left,X);
}
if(strcmp(BT->Data,X)<0){
//     printf("!%s##\n",X);
BT->Right=Insert(BT->Right,X);
}
if(strcmp(BT->Data,X)==0){
BT->Rate++;
return BT;
}
return BT;
}
void InstorderTraversal( BTree BT,int N ){
if(!BT)return ;
if((BT->Left==NULL)&&(BT->Right==NULL)){
printf("%s %.4lf%%\n",BT->Data,(BT->Rate/N)*100);
return ;
}
InstorderTraversal(BT->Left,N);
printf("%s %.4lf%%\n",BT->Data,(BT->Rate/N)*100);
InstorderTraversal(BT->Right,N);
return ;
}