【题目】求出1~n的整数中1出现的次数.(10进制)

 package com.exe11.offer;
/**
* 【题目】求出1~n的整数中1出现的次数.
* @author WGS
*
*/
public class NumberOf1 { public int getNumberOf1Between1AndN(int n){
if(n<=0) return 0;
if(n<=9) return 1;
int count=0;
for(int i=1;i<=n;i++){
count+=getCount(i);
}
return count; }
private int getCount(int n) {
int numberOf1=0;
int flag=0;
while(n!=0){
flag=n%10;
if(flag==1)
numberOf1++;
n=n/10;
}
return numberOf1;
}
public static void main(String[] args) {
NumberOf1 n=new NumberOf1();
int num=n.getNumberOf1Between1AndN(7);
System.out.println(num); } }
04-02 02:46