replaceElements

leetcode/replace_elements_with_greatest_element_on_right_side.go

@@ -0,0 +1,17 @@
+package leetcode
+
+func replaceElements(arr []int) []int {
+	if len(arr) == 0 {
+		return arr
+	}
+
+	rMax := -1
+	for i := len(arr) - 1; i >= 0; i-- {
+		v := arr[i]
+		arr[i] = rMax
+		if v >= rMax {
+			rMax = v
+		}
+	}
+	return arr
+}

leetcode/replace_elements_with_greatest_element_on_right_side_test.go

@@ -0,0 +1,25 @@
+package leetcode
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestReplaceElements(t *testing.T) {
+	cases := []struct {
+		input    []int
+		expected []int
+	}{
+		{
+			input:    []int{17, 18, 5, 4, 6, 1},
+			expected: []int{18, 6, 6, 6, 1, -1},
+		},
+	}
+
+	for _, c := range cases {
+		actual := replaceElements(c.input)
+		if !reflect.DeepEqual(actual, c.expected) {
+			t.Errorf("err")
+		}
+	}
+}