| 1 | // rec_mc1.rc |
| 2 | |
| 3 | fn rec_mc1(cashes: &[u32], amount: u32) -> u32 { |
| 4 | // 全用 1 元纸币时的最少找零纸币数 |
| 5 | let mut min_cashes = amount; |
| 6 | |
| 7 | if cashes.contains(&amount) { |
| 8 | return 1; |
| 9 | } else { |
| 10 | // 提取符合条件的币值 (找零币值肯定小于等于找零值) |
| 11 | for c in cashes.iter() |
| 12 | .filter(|&c| *c <= amount) |
| 13 | .collect::<Vec<&u32>>() { |
| 14 | // amount 减去 c，表示使用了一个面额为 c 的纸币 |
| 15 | // 所以要加 1 |
| 16 | let num_cashes = 1 + rec_mc1(&cashes, amount - c); |
| 17 | |
| 18 | // num_cashes 若比 min_cashes 小则更新 |
| 19 | if num_cashes < min_cashes { |
| 20 | min_cashes = num_cashes; |
| 21 | } |
| 22 | } |
| 23 | } |
| 24 | |
| 25 | min_cashes |
| 26 | } |
| 27 | |
| 28 | fn main() { |
| 29 | // cashes 保存各种面额的纸币 |