题解 | #杨辉三角(一)# | Rust

struct Solution{

}

impl Solution {
    fn new() -> Self {
        Solution{}
    }

    /**
    * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
    *
    * 
        * @param num int整型 
        * @return int整型二维数组
    */
    pub fn generate(&self, num: i32) -> Vec<Vec<i32>> {
        let mut ans:Vec<Vec<i32>> = Vec::with_capacity(num as usize);
        for i in 0..num as usize {
            let mut item:Vec<i32> = vec![1; i+1];
            for j in 1..i {
                item[j] = ans[i-1][j] + ans[i-1][j-1];
            }
            ans.push(item);
        }
        return ans;
    }
}