end 029

029_return_value_method/challenge_game/Program.cs

@@ -0,0 +1,45 @@
+Random random = new Random();
+
+Console.WriteLine("Would you like to play? (Y/N)");
+if (should_play()) {
+    play_game();
+}
+
+string win_or_lose(int target, int roll) {
+    if(roll > target){
+        return "You win!";
+    } else {
+        return "You lose!";
+    }
+}
+
+bool should_play() {
+    bool valid = false;
+    string? resp;
+    while (!valid) {
+        resp = Console.ReadLine();
+        if (resp != null) {
+            resp = resp.Trim().ToLower();
+            if(resp.Equals("y")){
+                return true;
+            } else if (resp.Equals("n")) {
+                return false;
+            }
+        }
+    }
+    return false;
+}
+
+void play_game() {
+    var play = true;
+    while (play) {
+        var target = random.Next(1,6);
+        var roll = random.Next(1,7);;
+        Console.WriteLine($"Roll a number greater than {target} to win!");
+        Console.WriteLine($"You rolled a {roll}");
+        Console.WriteLine(win_or_lose(target, roll));
+        Console.WriteLine("\nPlay again? (Y/N)");
+
+        play = should_play();
+    }
+}

029_return_value_method/challenge_game/challenge_game.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

029_return_value_method/return_array/Program.cs

@@ -0,0 +1,37 @@
+//int[] two_coins(int[] coins, int target) {
+int[,] two_coins(int[] coins, int target) {
+    int[,] result = {
+        {-1,-1},{-1,-1},{-1,-1},
+        {-1,-1},{-1,-1}
+    };
+    int count = 0;
+    for (int curr = 0; curr < coins.Length; curr++) {
+        for (int next = curr + 1; next < coins.Length; next++) {
+            if (coins[curr] + coins[next] == target) {
+                result[count, 0] = curr;
+                result[count, 1] = next;
+                count++;
+            }
+            if (count == result.GetLength(0)) {
+                return result;
+            }
+        }
+    }
+    return (count == 0) ? new int[0, 0] : result;
+}
+
+int target = 55;
+int[] coins = new int[] { 5, 5, 50, 25, 25, 10, 5 };
+int[,] result = two_coins(coins, target);
+
+if (result.Length == 0) {
+    Console.WriteLine("No two coins make change");
+} else {
+    Console.WriteLine("Change found at positions:");
+    for (int i = 0; i < result.GetLength(0); i++) {
+        if (result[i, 0] == -1) {
+            break;
+        }
+        Console.WriteLine($"{result[i, 0]},{result[i, 1]}");
+    }
+}

029_return_value_method/return_array/return_array.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

029_return_value_method/return_bool/Program.cs

@@ -0,0 +1,32 @@
+string[] words = { "racecar", "talented", "deified", "tent", "tenet" };
+
+Console.WriteLine("Is it a palindrome?");
+foreach (string word in words) {
+    Console.WriteLine($"{word}: {is_palindrome(word)}");
+    Console.WriteLine($"{word}: {check_palindrome(word)}");
+}
+
+bool is_palindrome(string word) {
+    int start = 0;
+    int end = word.Length - 1;
+
+    while (start < end) {
+        if (word[start] != word[end]) {
+            return false;
+        }
+        start++;
+        end--;
+    }
+    return true;
+}
+
+bool check_palindrome(string word) {
+    char[] temp = word.ToCharArray();
+    Array.Reverse(temp);
+    string rev_word = string.Join("", temp);
+    if (String.Equals(word, rev_word)) {
+        return true;
+    } else {
+        return false;
+    }
+}

029_return_value_method/return_bool/return_bool.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

029_return_value_method/return_meth/Program.cs

@@ -0,0 +1,25 @@
+double total = 0;
+double min_spend = 30.00;
+
+double[] items = {15.97, 3.50, 12.25, 22.99, 10.98};
+double[] discounts = {0.30, 0.00, 0.10, 0.20, 0.50};
+
+for (int i = 0; i < items.Length; i++) {
+    total += get_discounted_price(i);
+}
+
+total -= total_meets_minimum() ? 5.00 : 0.00;
+
+Console.WriteLine($"Total: ${format_decimal(total)}");
+
+double get_discounted_price(int item_index) {
+    return items[item_index] * (1 - discounts[item_index]);
+}
+
+bool total_meets_minimum() {
+    return total >= min_spend;
+}
+
+string format_decimal(double input) {
+    return input.ToString().Substring(0, 5);
+}

029_return_value_method/return_meth/return_meth.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

029_return_value_method/return_nums/Program.cs

@@ -0,0 +1,18 @@
+double usd = 23.73;
+int vnd = usd_to_vnd(usd);
+
+Console.WriteLine($"${usd} USD = ${vnd} VND");
+Console.WriteLine($"${vnd} VND = ${vnd_to_usd(vnd)} USD");
+
+int usd_to_vnd(double usd) {
+    int rate = 23500;
+    return (int) (rate * usd);
+}
+
+double vnd_to_usd(int vnd) {
+    double rate = 23500;
+    return vnd / rate;
+}
+
+var temp = 100*0.5;
+Console.WriteLine(temp.GetType());

029_return_value_method/return_nums/return_nums.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

029_return_value_method/return_str/Program.cs

@@ -0,0 +1,22 @@
+string reverse_word(string word) {
+    string result = "";
+    for (int i=word.Length - 1; i>=0 ; i--) {
+          result += word[i];
+    }
+    return result;
+}
+
+string reverse_sentence(string input) {
+    string result = "";
+    string[] words = input.Split(" ");
+    foreach (string word in words) {
+        result += reverse_word(word) + " ";
+    }
+    return result.Trim();
+}
+
+string input = "there are snakes at the zoo";
+
+Console.WriteLine("Sentece : " + input);
+Console.WriteLine("Reversed: " + reverse_word(input));
+Console.WriteLine("Special : " + reverse_sentence(input));

029_return_value_method/return_str/return_str.csproj

@@ -0,0 +1,10 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net8.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+  </PropertyGroup>
+
+</Project>

README.md

@@ -33,3 +33,4 @@ Following
 26. [Challenge - variable data](./026_Challenge_variable_data/026_csharp.md)
 27. [Create methods](./027_create_methods/027_csharp.md)
 28. [Methods with parameters](./028_method_parameters/028_csharp.md)
+29. [Methods that return values](./029_return_value_method/029_csharp.md)