小编hen*_*biq的帖子

我有一个二维矢量:

let vec2d = vec![
    vec![1, 1, 1],
    vec![1, 1, 1],
];

我可以通过这种方式生成存储的元素总数:

let mut n_vec_element: i32 = 0;

for i in vec2d.iter() {
    n_vec_element += i.len() as i32;
}

println!("2D vector elements :{}", n_vec_element); // prints 6

当我增加尺寸时,循环变长:

let mut n_vec_element: i32 = 0;

let vec3d = vec![
    vec![
        vec![1, 3, 5 as i32],
        vec![2, 4, 6 as i32],
        vec![3, 5, 7 as i32],
    ],
    vec![
        vec![1, 3, 5 as i32],
        vec![2, 4, 6 as i32],
        vec![3, 5, 7 …