| use std::error::Error; |
| use std::io; |
| use std::process; |
| |
| use serde::Deserialize; |
| |
| #[derive(Debug, Deserialize)] |
| #[serde(rename_all = "PascalCase")] |
| struct Record { |
| country: String, |
| city: String, |
| accent_city: String, |
| region: String, |
| population: Option<u64>, |
| latitude: f64, |
| longitude: f64, |
| } |
| |
| fn run() -> Result<u64, Box<dyn Error>> { |
| let mut rdr = csv::Reader::from_reader(io::stdin()); |
| |
| let mut count = 0; |
| for result in rdr.deserialize() { |
| let record: Record = result?; |
| if record.country == "us" && record.region == "MA" { |
| count += 1; |
| } |
| } |
| Ok(count) |
| } |
| |
| fn main() { |
| match run() { |
| Ok(count) => { |
| println!("{}", count); |
| } |
| Err(err) => { |
| println!("{}", err); |
| process::exit(1); |
| } |
| } |
| } |