C++中最小项和的快速计算？

#include <iostream>

int calculateMinItemSum(int num) {
    int sum = 0;
    
    while (num > 0) {
        sum += num & 1;
        num >>= 1;
    }
    
    return sum;
}

int main() {
    int num = 5;
    int minItemSum = calculateMinItemSum(num);
    
    std::cout << "The minimum item sum of " << num << " is: " << minItemSum << std::endl;
    
    return 0;
}

The minimum item sum of 5 is: 2

#include <iostream>
#include <vector>

int calculateMinItemSum(int num) {
    std::vector<int> dp(num + 1, 0);
    
    for (int i = 1; i <= num; i++) {
        dp[i] = dp[i >> 1] + (i & 1);
    }
    
    return dp[num];
}

int main() {
    int num = 5;
    int minItemSum = calculateMinItemSum(num);
    
    std::cout << "The minimum item sum of " << num << " is: " << minItemSum << std::endl;
    
    return 0;
}

The minimum item sum of 5 is: 2