28 lines
833 B
Rust
28 lines
833 B
Rust
use std::collections::HashMap;
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/**
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* dp[i] 表示进行i次删除首字母操作后得到的结果
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*/
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fn main() {
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let mut buf = String::new();
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std::io::stdin().read_line(&mut buf).ok();
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let t: usize = buf.trim().parse::<usize>().unwrap();
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for _ in 0..t {
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buf.clear();
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std::io::stdin().read_line(&mut buf).ok();
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let n: usize = buf.trim().parse::<usize>().unwrap();
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buf.clear();
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std::io::stdin().read_line(&mut buf).ok();
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let a = buf.trim().parse::<String>().unwrap().into_bytes();
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let mut res = 0;
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let mut mp = HashMap::new();
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let mut dp = vec![0;n+1];
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for i in (0..n).rev() {
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dp[i] = mp.get(&a[i]).unwrap_or(&n) - i;
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res += dp[i];
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mp.insert(a[i], i);
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}
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println!("{}", res);
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}
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} |