...ked at 'index out of bounds: the len is 1 but the index is 1', src/main.rs:20:21
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
minigrep on master [?] is 📦 0.1.0 via 🦀 1.67.1
➜
```
### 优化一：
```rust
use std::env;
use std::fs;
fn ma...