Fenwick Construction Algorithm

#define n 100
#include <iostream>
#include <math.h>

int tree[n];
int arr[n] = { /*...values...*/ };

int main(int argc, char *argv[]) {
    for(int i=1; i<=n; i++) {
        int tree_val = arr[i];
        int incrementer = (i&(-i))>>1;
        for(int index = (i-(incrementer<<1))+incrementer; incrementer>0; incrementer>>=1, index+=incrementer) {
            tree_val+=tree[index];
        }
        tree[i] = tree_val;
    }
}