Compilare: warning: unused import: `std::fs` --> main.rs:1:5 | 1 | use std::fs; | ^^^^^^^ | = note: `#[warn(unused_imports)]` on by default warning: unused import: `Read` --> main.rs:3:53 | 3 | use std::io::{BufRead, BufReader, BufWriter, Write, Read}; | ^^^^ warning: variable does not need to be mutable --> main.rs:13:9 | 13 | let mut arr:Vec <usize> = line.trim().split_whitespace().map(|x| x.parse().unwrap()).collect(); | ----^^^ | | | help: remove this `mut` | = note: `#[warn(unused_mut)]` on by default warning: variable does not need to be mutable --> main.rs:22:13 | 22 | let mut row : Vec<i32> = line.trim().split_whitespace().map(|x| x.parse().unwrap()).collect(); | ----^^^ | | | help: remove this `mut` warning: variable `FIN` should have a snake case name --> main.rs:7:13 | 7 | let mut FIN = BufReader::new(File::open("file.in").unwrap()); | ^^^ help: convert the identifier to snake case: `fin` | = note: `#[warn(non_snake_case)]` on by default warning: variable `FOUT` should have a snake case name --> main.rs:8:13 | 8 | let mut FOUT = BufWriter::new(File::create("file.out").unwrap()); | ^^^^ help: convert the identifier to snake case: `fout` warning: 6 warnings emitted