树种统计

这是陈越数据结构的4-2，用c++改了一下，主体还是原来的程序，有一些细节改成了C++

#include
#include
#include

#include 	//gets()需要这两个头文件
#include 

#include 	//设置精度需要这个头文件

const int Maxsize = 30;
using namespace std;
typedef struct TNode * BinTree;
struct TNode {
	char treename[Maxsize + 1];
	int count;
	BinTree left;
	BinTree right;
};
BinTree Insert(BinTree BT, char * name)
{
	if (!BT)
	{
		BT = new struct TNode;
		strcpy(BT->treename, name);
		BT->count = 1;
		BT->left = BT->right = NULL;
	}
	else
	{
		int cmp = strcmp(BT->treename, name);
		if (cmp < 0)BT->right = Insert(BT->right, name);
		else if (cmp > 0)BT->left = Insert(BT->left, name);
		else
			BT->count++;
	}
	return BT;
}
void Output(BinTree BT, int N)
{
	if (!BT)return;
	else
	{
		Output(BT->left, N);
		cout << BT->treename << " " << setiosflags(ios::fixed) << setprecision(4) << (double)BT->count / (double)N * 100.0 << "%" << endl;
		Output(BT->right, N);
	}
}
int main()
{
	BinTree BT = NULL;
	int N;
	cin >> N;
	cin.get();
	for (int i = 0; i

关于设置输出精度

 cout << setiosflags(ios::fixed) <(6) << endl;  为输出六位小数（小数点后保留6位）

cout << setprecision(3) << endl;为输出3位有效数字