求出1~13的整数中1出现的次数,并算出100~1300的整数中1出现的次数？为此他特别数了一下1~13中包含1的数字有1、10、11、12、13因此共出现6次,但是对于后面问题他就没辙了。ACMer希望你们帮帮他,并把问题更加普遍化,可以很快的求出任意非负整数区间中1出现的次数。

// test20.cpp : 定义控制台应用程序的入口点。

//

include "stdafx.h"

include

include

include

include

include

include

include<string.h>

include

using namespace std;

class Solution {

public:

int NumberOf1Between1AndN_Solution(int n)

{

// int num=1;

int count = 0;

for (int i = 0;i <= n;i++)

{

int num = i;

do {

if (num % 10 == 1)

{

++count;

}

num = num / 10;

} while (num!=0);

}

	return count;
}

};

int main()

{

Solution so;
//int count=so.NumberOf1Between1AndN_Solution(13);
cout <<"count:" << so.NumberOf1Between1AndN_Solution(1)<< endl;

cout << endl;
return 0;

}