sort: add examples for IntsAreSorted, Float64s and Float64sAreSorted

Change-Id: Ib4883470bd2271e546daea3156d4a48dd873aaa3
Reviewed-on: https://go-review.googlesource.com/57670
Reviewed-by: Joe Tsai <thebrokentoaster@gmail.com>
Run-TryBot: Joe Tsai <thebrokentoaster@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

src/sort/example_test.go

@@ -6,6 +6,7 @@ package sort_test
 
 import (
 	"fmt"
+	"math"
 	"sort"
 )
 
@@ -16,6 +17,49 @@ func ExampleInts() {
 	// Output: [1 2 3 4 5 6]
 }
 
+func ExampleIntsAreSorted() {
+	s := []int{1, 2, 3, 4, 5, 6} // sorted ascending
+	fmt.Println(sort.IntsAreSorted(s))
+
+	s = []int{6, 5, 4, 3, 2, 1} // sorted descending
+	fmt.Println(sort.IntsAreSorted(s))
+
+	s = []int{3, 2, 4, 1, 5} // unsorted
+	fmt.Println(sort.IntsAreSorted(s))
+
+	// Output: true
+	// false
+	// false
+}
+
+func ExampleFloat64s() {
+	s := []float64{5.2, -1.3, 0.7, -3.8, 2.6} // unsorted
+	sort.Float64s(s)
+	fmt.Println(s)
+
+	s = []float64{math.Inf(1), math.NaN(), math.Inf(-1), 0.0} // unsorted
+	sort.Float64s(s)
+	fmt.Println(s)
+
+	// Output: [-3.8 -1.3 0.7 2.6 5.2]
+	// [NaN -Inf 0 +Inf]
+}
+
+func ExampleFloat64sAreSorted() {
+	s := []float64{0.7, 1.3, 2.6, 3.8, 5.2} // sorted ascending
+	fmt.Println(sort.Float64sAreSorted(s))
+
+	s = []float64{5.2, 3.8, 2.6, 1.3, 0.7} // sorted descending
+	fmt.Println(sort.Float64sAreSorted(s))
+
+	s = []float64{5.2, 1.3, 0.7, 3.8, 2.6} // unsorted
+	fmt.Println(sort.Float64sAreSorted(s))
+
+	// Output: true
+	// false
+	// false
+}
+
 func ExampleReverse() {
 	s := []int{5, 2, 6, 3, 1, 4} // unsorted
 	sort.Sort(sort.Reverse(sort.IntSlice(s)))