↓ 1 callersFunctionget_concatenation1929 https://leetcode-cn.com/problems/concatenation-of-array/ [1,2,1] [1,2,1,1,2,1] 审题,函数输入已经固定是 immut vec,那么结果不能用他返回 所以需要declare 2 个mut 的nums
1929-concatenation-of-array.rs:11
Methodbacktrace(n: i32, k: usize, start_index: i32, path: &mut Vec<i32>, ret: &mut Vec<Vec<i32>>, sum: i32)
216-combination-sum-iii.rs:5