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#include "stdafx.h"

#include <vector>

using namespace std;

class Solution {

public:

vector<int> countBits(int num) {

// GCC内建函数__builtin_popcount (unsigned u)

//std::vector<int> ret;

//for (int i = 0;i <= num;i++)

//{

// ret.push_back(__builtin_popcount(i));

//}

//return ret;

// 时间复杂度为O(n * sizeof(integer))

// int count=0;

// vector<int> dp(num+1,0);

// for(int i=0;i<num+1;i++){

// int j=i;

// int count=0;

// while(j){

// if(j&1)

// count++;

// j=j>>1;

// }

// dp[i]=count;

// }

// return dp;

// 线性时间O(n)

vector<int> dp(num + 1, 0);

for (int i = 1;i <= num;i++) {

dp[i] = dp[i&i - 1] + 1;

}

return dp;

}

};