Question

How to implement a cumulative sum of numbers in an int array in Rust

Answer 1

// 0 : 0+1=1 : 0+1+2=3 : 0+1+2+3=6 : 0+1+2+3+4=10 : 0+1+2+3+4+5=15 ...

fn cumulative_sum_of_int_array(arr: &[i32]) -> Vec<i32> {
    let mut sum_arr = Vec::with_capacity(arr.len());
    let mut sum = 0;
    
    for &num in arr {
        sum += num;
        sum_arr.push(sum);
    }
    
    sum_arr
}

fn main() {
    let arr = &[0, 1, 2, 3, 4, 5, 6];
    
    let sum_arr = cumulative_sum_of_int_array(arr);
    
    for &num in &sum_arr {
        print!("{} ", num);
    }
}

  
    
/*
run:
  
0 1 3 6 10 15 21 
  
*/

 

70+ SQL courses for beginners and professionals