Merge pull request #21 from storopoli/storopoli/zig

feat: zig examples

.devcontainer/devcontainer.json

@@ -1,16 +1,15 @@
 {
 	"name": "Graphs and Algorithmic Complexity",
 	"image": "mcr.microsoft.com/devcontainers/base:alpine",
-
-	"postCreateCommand": "sudo apk update && sudo apk add just typst gdb",
-
+	"postCreateCommand": "sudo apk update && sudo apk add just typst gdb zig",
 	"customizations": {
 		"vscode": {
 			"extensions": [
 				"ms-vscode.cpptools",
 				"vadimcn.vscode-lldb",
+				"ziglang.vscode-zig",
 				"myriad-dreamin.tinymist"
 			]
 		}
 	}
-}
+}

.github/workflows/c-code.yml

@@ -0,0 +1,18 @@
+name: c-code
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  clang-format:
+    name: Check if C code compiles and runs
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Setup just
+        uses: extractions/setup-just@v2
+      - name: Compile and run C code
+        run: just c-run

.github/workflows/zig-code.yml

@@ -0,0 +1,20 @@
+name: zig-code
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  clang-format:
+    name: Check if zig code compiles and runs
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Setup zig
+        uses: mlugg/setup-zig@v1
+      - name: Setup just
+        uses: extractions/setup-just@v2
+      - name: Compile and run zig code
+        run: just z-run

.github/workflows/zig-fmt.yml

@@ -0,0 +1,18 @@
+name: zig-fmt
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  clang-format:
+    name: Check if zig code is formatted
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+      - name: Setup zig
+        uses: mlugg/setup-zig@v1
+      - name: Check zig code format
+        run: zig fmt --check ./code/zig/*.zig

.gitignore

@@ -3,4 +3,7 @@
 
 # C++
 *.out
-*.exe
+*.exe
+
+# Output
+output/

README-pt.md

@@ -1,6 +1,8 @@
 # Teoria dos Grafos e Complexidade Computacional
 
 [![CC0](https://img.shields.io/badge/License-CC0-lightgrey.svg)](https://creativecommons.org/publicdomain/zero/1.0/)
+[![C code](https://img.shields.io/badge/code-C-blue)](./code/c)
+[![Zig code](https://img.shields.io/badge/code-Zig-orange)](./code/zig)
 [![Rodar no Repl.it](https://repl.it/badge/github/storopoli/grafos-complexidade)](https://repl.it/github/storopoli/grafos-complexidade)
 [![Abrir no Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/storopoli/grafos-complexidade)
 
@@ -30,9 +32,15 @@
 1. Divisão e Conquista; e
 1. Algoritmos Gulosos.
 
+## Exemplos de Código
+A principal linguagem de programação usada para os exemplos é C.
+Também há exemplos em Zig.
+Confira-os nos diretórios `code/c/` e `code/zig/`, respectivamente.
+
 ## Dependências
 
-- Compilador C/C++; e
+- Compilador C/C++;
+- (Opcional) compilador [Zig](https://ziglang.org); e
 - [`typst`](https://typst.app) para os slides.
 
 Os slides são gerados usando [Typst](https://typst.app) com GitHub Actions

README.md

@@ -1,6 +1,8 @@
 # Graph Theory and Computational Complexity
 
 [![CC0](https://img.shields.io/badge/License-CC0-lightgrey.svg)](https://creativecommons.org/publicdomain/zero/1.0/)
+[![C code](https://img.shields.io/badge/code-C-blue)](./code/c)
+[![Zig code](https://img.shields.io/badge/code-Zig-orange)](./code/zig)
 [![Run on Repl.it](https://repl.it/badge/github/storopoli/grafos-complexidade)](https://repl.it/github/storopoli/grafos-complexidade)
 [![Open in Gitpod](https://gitpod.io/button/open-in-gitpod.svg)](https://gitpod.io/#https://github.com/storopoli/grafos-complexidade)
 
@@ -30,9 +32,16 @@
 1. Divide and Conquer; and
 1. Greedy Algorithms.
 
+## Code Examples
+
+The primary programming language used for examples is C.
+Also there are [Zig](https://ziglang.org) examples.
+Check them at `code/c/` and `code/zig/` directories, respectively.
+
 ## Dependencies
 
-- C/C++ Compiler; and
+- C/C++ Compiler;
+- (Optional) [Zig](https://ziglang.org) compiler; and
 - [`typst`](https://typst.app) for the slides.
 
 The slides are generated using [Typst](https://typst.app) with GitHub Actions

code/zig/01-graphs_eulerian_path.zig

@@ -0,0 +1,139 @@
+const std = @import("std");
+const print = std.debug.print;
+
+/// Number of vertices in the graph
+const N = 5;
+/// Maximum length of the path
+const MAX_PATH_LENGTH = 20;
+
+/// Find Eulerian Path in a graph
+///
+/// # Parameters
+///
+/// - `graph`: Adjacency matrix of the graph
+fn findPath(graph: *[N][N]i32) void {
+    var numofadj: [N]i32 = [_]i32{0} ** N;
+    var stack: [N]i32 = [_]i32{0} ** N;
+    var path: [MAX_PATH_LENGTH]i32 = [_]i32{0} ** MAX_PATH_LENGTH;
+    var top: usize = 0;
+    var path_length: usize = 0;
+
+    // Find out number of edges each vertex has
+    for (0..N) |i| {
+        for (0..N) |j| {
+            numofadj[i] += graph.*[i][j];
+        }
+    }
+
+    // Find out how many vertices have an odd number of edges
+    var startpoint: usize = 0;
+    var numofodd: i32 = 0;
+    var idx_i: usize = N;
+    while (idx_i > 0) : (idx_i -= 1) {
+        const idx = idx_i - 1;
+        if (@mod(numofadj[idx], 2) == 1) {
+            numofodd += 1;
+            startpoint = idx;
+        }
+    }
+
+    // If the number of vertices with odd number of edges is greater than two, return "No Solution".
+    if (numofodd > 2) {
+        print("No Solution\n", .{});
+        return;
+    }
+
+    // Initialize empty stack and path; take the starting current as discussed
+    var cur: usize = startpoint;
+
+    // Loop will run until there is an element in the stack or current vertex has some neighbor.
+    while (top > 0 or numofadj[cur] > 0) {
+        // If current node has no neighbors, add it to path and pop stack; set new current to the popped element
+        if (numofadj[cur] == 0) {
+            path[path_length] = @intCast(cur);
+            path_length += 1;
+            if (top > 0) {
+                top -= 1;
+                cur = @intCast(stack[top]);
+            } else {
+                break;
+            }
+        }
+        // If the current vertex has at least one neighbor, add the current vertex to stack,
+        // remove the edge between them, and set the current to its neighbor.
+        else {
+            for (0..N) |j| {
+                if (graph.*[cur][j] == 1) {
+                    stack[top] = @intCast(cur);
+                    top += 1;
+                    graph.*[cur][j] = 0;
+                    graph.*[j][cur] = 0;
+                    numofadj[cur] -= 1;
+                    numofadj[j] -= 1;
+                    cur = j;
+                    break;
+                }
+            }
+        }
+    }
+
+    // Add the last vertex to the path
+    path[path_length] = @intCast(cur);
+    path_length += 1;
+
+    // Print the path
+    var idx: usize = path_length;
+    while (idx > 0) : (idx -= 1) {
+        print("{d} -> ", .{path[idx - 1]});
+    }
+    print("\n", .{});
+}
+
+/// Main function
+pub fn main() !void {
+    // Test case 1:
+    // 0 --- 1
+    // |    | \
+    // |    2--3
+    // 4
+    var graph1: [N][N]i32 = .{
+        .{ 0, 1, 0, 0, 1 },
+        .{ 1, 0, 1, 1, 0 },
+        .{ 0, 1, 0, 1, 0 },
+        .{ 0, 1, 1, 0, 0 },
+        .{ 1, 0, 0, 0, 0 },
+    };
+
+    print("Test Case 1:\n", .{});
+    findPath(&graph1);
+
+    // Test case 2:
+    //   0 -- 1 -- 2
+    //  /|  / \  | \
+    // 3--4      5
+    var graph2: [N][N]i32 = .{
+        .{ 0, 1, 0, 1, 1 },
+        .{ 1, 0, 1, 0, 1 },
+        .{ 0, 1, 0, 1, 1 },
+        .{ 1, 0, 1, 0, 0 },
+        .{ 1, 1, 1, 0, 0 },
+    };
+
+    print("Test Case 2:\n", .{});
+    findPath(&graph2);
+
+    // Test case 3:
+    //   0 --- 1
+    //  /|\     |\
+    // 2  4---5  3
+    var graph3: [N][N]i32 = .{
+        .{ 0, 1, 1, 0, 1 },
+        .{ 1, 0, 0, 1, 1 },
+        .{ 1, 0, 0, 1, 0 },
+        .{ 0, 1, 1, 0, 1 },
+        .{ 1, 1, 0, 1, 0 },
+    };
+
+    print("Test Case 3:\n", .{});
+    findPath(&graph3);
+}