correct sums of freqs

.gitignore

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+/target

Cargo.lock

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+# This file is automatically @generated by Cargo.
+# It is not intended for manual editing.
+version = 4
+
+[[package]]
+name = "ngram-counter"
+version = "0.1.0"

Cargo.toml

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+[package]
+name = "ngram-counter"
+version = "0.1.0"
+edition = "2024"
+
+[dependencies]

src/main.rs

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+use std::{
+    collections::HashMap,
+    io::{self, Read},
+};
+
+fn main() {
+    let mut src = Vec::new();
+    io::stdin().read_to_end(&mut src).unwrap();
+
+    for n in 1..2 {
+        let freqs = ngram_freqs(n, &src);
+        println!("{}", freqs.values().sum::<f64>());
+    }
+}
+
+fn ngram_freqs(n: usize, src: &[u8]) -> HashMap<Box<[u8]>, f64> {
+    assert!(n > 0);
+
+    let mut counts: HashMap<Box<[u8]>, u64> = HashMap::new();
+
+    for ngram in src.windows(n) {
+        *counts.entry(Box::from(ngram)).or_default() += 1;
+    }
+
+    let total_count: u64 = counts.values().sum();
+
+    counts
+        .into_iter()
+        .map(|(k, v)| (k, v as f64 / total_count as f64))
+        .collect()
+}