Add solution for Challenge 19 by chenyao0910(RezaSi#314)

Author: chenyao0910

challenge-19/submissions/chenyao0910/solution-template.go

@@ -0,0 +1,81 @@
+package main
+
+import (
+	"fmt"
+)
+
+func main() {
+	// Example slice for testing
+	numbers := []int{3, 1, 4, 1, 5, 9, 2, 6}
+
+	// Test FindMax
+	max := FindMax(numbers)
+	fmt.Printf("Maximum value: %d\n", max)
+
+	// Test RemoveDuplicates
+	unique := RemoveDuplicates(numbers)
+	fmt.Printf("After removing duplicates: %v\n", unique)
+
+	// Test ReverseSlice
+	reversed := ReverseSlice(numbers)
+	fmt.Printf("Reversed: %v\n", reversed)
+
+	// Test FilterEven
+	evenOnly := FilterEven(numbers)
+	fmt.Printf("Even numbers only: %v\n", evenOnly)
+}
+
+// FindMax returns the maximum value in a slice of integers.
+// If the slice is empty, it returns 0.
+func FindMax(numbers []int) int {
+	// TODO: Implement this function
+	if len(numbers) == 0{
+	    return 0
+	}
+	mx := numbers[0]
+	for i:=1 ; i < len(numbers);i++{
+	    if(numbers[i] > mx){
+	         mx = numbers[i]
+	    }
+	}
+	return mx
+}
+
+// RemoveDuplicates returns a new slice with duplicate values removed,
+// preserving the original order of elements.
+  func RemoveDuplicates(numbers []int) []int {
+      seen := make(map[int]bool)
+      n := make([]int, 0, len(numbers))
+
+      for _, num := range numbers {
+          if !seen[num] {  
+              seen[num] = true
+              n = append(n, num)
+          }
+      }
+      return n
+  }
+
+// ReverseSlice returns a new slice with elements in reverse order.
+func ReverseSlice(slice []int) []int {
+	n := make([]int, len(slice))
+	for i:=len(slice) - 1 ; i >= 0 ; i--{
+	    // 2 1 0
+	    // 0 1 2
+	    n[len(slice) - i - 1] = slice[i]
+	}
+	return n
+}
+
+// FilterEven returns a new slice containing only the even numbers
+// from the original slice.
+func FilterEven(numbers []int) []int {
+    n := make([]int , 0, len(numbers))
+    for i:=0 ; i < len(numbers);i++{
+        if(numbers[i] % 2 == 0){
+            n = append(n, numbers[i])
+        }
+    }
+	// TODO: Implement this function
+	return n
+}