29 lines
588 B
Rust
29 lines
588 B
Rust
use std::io::{read_to_string, stdin};
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fn main() {
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let temp = read_to_string(stdin()).unwrap();
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let mut iter = temp
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.split_ascii_whitespace()
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.map(|x| x.parse::<i32>().unwrap());
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let n = iter.next().unwrap() as usize;
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let mut chems = (0..n)
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.map(|_| (iter.next().unwrap(), iter.next().unwrap()))
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.collect::<Vec<_>>();
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chems.sort_by_key(|x| x.1);
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let mut pin = chems[0].1;
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let mut cnt = 1;
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for (x, y) in chems {
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if x > pin {
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cnt += 1;
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pin = y;
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}
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}
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println!("{}", cnt);
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}
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