322.coin change

Cargo.toml

@@ -1,4 +1,14 @@
 [package]
 name= "leetcode-practice"
 version = "0.1.0"
-edition = "2021"
+edition = "2021"
+
+[dev-dependencies]
+criterion = { version = "0.8", features = ["html_reports"] }
+
+[[bench]]
+name = "coin_change"
+harness = false
+
+[dependencies]
+plotters = "0.3.7"

benches/coin_change.rs

@@ -0,0 +1,71 @@
+/*
+  このコードはGPT-5.1を利用して出力しました。
+*/
+
+use leetcode_practice::chart::draw_multi_line_chart;
+use leetcode_practice::solutions::*;
+
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let coins = vec![1, 2, 5, 186, 419, 83, 408];
+    let inputs = vec![10, 20, 40, 80, 160, 320, 6249];
+
+    // A vs B vs C の複数シリーズ
+    let mut series: Vec<(&str, Vec<(f64, f64)>)> = vec![];
+
+    let mut recursive_dfs = vec![];
+    for amount in &inputs {
+        let t = measure(|| step1a::Solution::coin_change(coins.clone(), *amount));
+        recursive_dfs.push((*amount as f64, t));
+    }
+    series.push(("recursive_dfs(step1a.rs)", recursive_dfs));
+
+    let mut bfs = vec![];
+    for amount in &inputs {
+        let t = measure(|| step1b_bfs::Solution::coin_change(coins.clone(), *amount));
+        bfs.push((*amount as f64, t));
+    }
+    series.push(("bfs(step1b_bfs.rs)", bfs));
+
+    let mut dp = vec![];
+    for amount in &inputs {
+        let t = measure(|| step1c_dp::Solution::coin_change(coins.clone(), *amount));
+        dp.push((*amount as f64, t));
+    }
+    series.push(("dp(step1c_dp.rs)", dp));
+
+    let mut bfs_v2 = vec![];
+    for amount in &inputs {
+        let t = measure(|| step2_bfs::Solution::coin_change(coins.clone(), *amount));
+        bfs_v2.push((*amount as f64, t));
+    }
+    series.push(("bfs_v2(step2_bfs.rs)", bfs_v2));
+
+    let mut dp_v2 = vec![];
+    for amount in &inputs {
+        let t = measure(|| step2a_dp::Solution::coin_change(coins.clone(), *amount));
+        dp_v2.push((*amount as f64, t));
+    }
+    series.push(("dp_v2(step2a_dp)", dp_v2));
+
+    // グラフ出力
+    draw_multi_line_chart(
+        "multi_line.svg",
+        &series,
+        "runtime comparison",
+        "amount",
+        "time per call [ns]",
+    )?;
+
+    println!("multi_line.png を出力しました！");
+    Ok(())
+}
+
+/// 単純な計測関数：closure を N 回実行し平均 ns を返す
+fn measure<F: Fn() -> i32>(f: F) -> f64 {
+    let repeat = 200;
+    let start = std::time::Instant::now();
+    for _ in 0..repeat {
+        f();
+    }
+    start.elapsed().as_nanos() as f64 / repeat as f64
+}

src/chart.rs

@@ -0,0 +1,94 @@
+/*
+  このコードはGPT-5.1を利用して出力しました。
+*/
+use plotters::prelude::*;
+
+/// マルチライン折れ線グラフを SVG に出力する
+///
+/// `series` は以下形式：
+/// [
+///   ("step1", vec![(x, y), (x, y), ...]),
+///   ("step1c_dp", vec![(x, y), (x, y), ...]),
+///   ("step3", vec![(x, y), ...]),
+/// ]
+pub fn draw_multi_line_chart(
+    path: &str, // "multi_line.svg"
+    series: &[(&str, Vec<(f64, f64)>)],
+    title: &str,
+    x_label: &str,
+    y_label: &str,
+) -> Result<(), Box<dyn std::error::Error>> {
+    if series.is_empty() {
+        return Ok(());
+    }
+
+    // ----------------- 軸の最小・最大を求める -----------------
+
+    let mut min_x = f64::INFINITY;
+    let mut max_x = f64::NEG_INFINITY;
+    let mut min_y = f64::INFINITY;
+    let mut max_y = f64::NEG_INFINITY;
+
+    for (_, pts) in series {
+        for (x, y) in pts {
+            min_x = min_x.min(*x);
+            max_x = max_x.max(*x);
+            min_y = min_y.min(*y);
+            max_y = max_y.max(*y);
+        }
+    }
+
+    // Plotters の都合で min==max だと描けないため少し広げる
+    if (min_x - max_x).abs() < f64::EPSILON {
+        min_x -= 1.0;
+        max_x += 1.0;
+    }
+    if (min_y - max_y).abs() < f64::EPSILON {
+        min_y -= 1.0;
+        max_y += 1.0;
+    }
+
+    // ----------------- SVG の描画領域作成 -----------------
+
+    let root = SVGBackend::new(path, (1000, 600)).into_drawing_area();
+    root.fill(&WHITE)?;
+
+    let mut chart = ChartBuilder::on(&root)
+        .caption(title, ("sans-serif", 24))
+        .margin(20)
+        .x_label_area_size(50)
+        .y_label_area_size(60)
+        .build_cartesian_2d(min_x..max_x, min_y..max_y)?;
+
+    chart
+        .configure_mesh()
+        .x_desc(x_label)
+        .y_desc(y_label)
+        .draw()?;
+
+    // ----------------- 色リスト（必要に応じて追加可能） -----------------
+
+    let colors = vec![&RED, &BLUE, &GREEN, &MAGENTA, &CYAN, &BLACK];
+
+    // ----------------- 複数シリーズの描画 -----------------
+
+    for (idx, (name, pts)) in series.iter().enumerate() {
+        let color = colors[idx % colors.len()];
+
+        chart
+            .draw_series(LineSeries::new(pts.clone(), color.stroke_width(3)))?
+            .label(*name)
+            .legend(move |(x, y)| PathElement::new([(x, y), (x + 20, y)], color.stroke_width(3)));
+    }
+
+    // ----------------- 凡例（レジェンド）表示 -----------------
+
+    chart
+        .configure_series_labels()
+        .border_style(&BLACK)
+        .background_style(&WHITE.mix(0.8))
+        .draw()?;
+
+    root.present()?;
+    Ok(())
+}

src/lib.rs

@@ -1 +1,3 @@
 // Rust-Analyzerを動作させるために空ファイルを置いています。
+pub mod chart;
+pub mod solutions;

src/solutions/mod.rs

@@ -0,0 +1,5 @@
+pub mod step1a;
+pub mod step1b_bfs;
+pub mod step1c_dp;
+pub mod step2_bfs;
+pub mod step2a_dp;