292. Nim Game

From today onwards, brush a leetcode every day.

Today's topic is simple: Given a non negative integer number num. For every numbers I in the range 0≤i≤num calculate the number of 1 ' s in their binary representation and return them as An array.

Initial thinking: double loop, outer loop number, inner layer statistics ' 1 ' occurrences.

New knowledge: ArrayList to int array mode;

Binary conversion.

Solve:

 Packagecom.wang.test;Importjava.util.ArrayList;Importjava.util.List;/*@Tittle * 338.  Counting Bits * Given a non negative integer number num. * For every numbers I in the range 0≤i≤num * Calculate the number of 1 ' s in their binary representation and return th EM as an array. * @auther: Wanglin * @time: 2016/04/11*/ Public classCountingbits { Public int[] Countbits (intnum) {List List=NewArrayList ();  for(intn = 0; n <= num; ++N) {//Binarynum receiving a number converted into binaryString Binarynum =integer.tobinarystring (n); Char[] Chararr =Binarynum.tochararray (); inti = 0;  for(intm = 0; M < chararr.length; ++m) {if(Chararr[m] = = ' 1 ') {i++;        }} list.add (i); }        int[] res =New int[List.size ()];  for(inti = 0; I < list.size (); i++) {Res[i]=(Integer) list.get (i); }        returnRes; }     Public Static voidMain (string[] args) {int[] res =NewCountingbits (). Countbits (5);  for(inti:res)        {System.out.print (i); }    }}

292. Nim Game