c++実装統計文字列における各文字の個数

#include<iostream>
#include<string>

using namespace std;

void tongji(char*,int);

int main()
{
	char a[100];
	cout<<"      :";
	gets_s(a);
	int n=strlen(a);
	cout<<"     :"<<endl;
	cout<<a<<endl;
	tongji(a,n);
	system("pause");
	return 0;
}


void tongji(char s[],int s1)
{
	int num=0,str=0,space=0,other=0;
	for(int i=0;i<s1;i++)
	{
		if((s[i]>='a'&&s[i]<='z')||(s[i]>='A'&&s[i]<='Z'))
			++str;
		else if(s[i]>='0'&&s[i]<='9')
			++num;
		else if(s[i]==' ')
			++space;
		else ++other;
	}
	cout<<"  :"<<str<<endl;
	cout<<"  :"<<num<<endl;
	cout<<"  :"<<space<<endl;
	cout<<"    :"<<other<<endl;
}