Your IP : 172.28.240.42
// Copyright 2023 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package slices
import (
"cmp"
"fmt"
"math"
"math/rand"
"sort"
"strconv"
"strings"
"testing"
)
var ints = [...]int{74, 59, 238, -784, 9845, 959, 905, 0, 0, 42, 7586, -5467984, 7586}
var float64s = [...]float64{74.3, 59.0, math.Inf(1), 238.2, -784.0, 2.3, math.Inf(-1), 9845.768, -959.7485, 905, 7.8, 7.8, 74.3, 59.0, math.Inf(1), 238.2, -784.0, 2.3}
var float64sWithNaNs = [...]float64{74.3, 59.0, math.Inf(1), 238.2, -784.0, 2.3, math.NaN(), math.NaN(), math.Inf(-1), 9845.768, -959.7485, 905, 7.8, 7.8}
var strs = [...]string{"", "Hello", "foo", "bar", "foo", "f00", "%*&^*&^&", "***"}
func TestSortIntSlice(t *testing.T) {
data := Clone(ints[:])
Sort(data)
if !IsSorted(data) {
t.Errorf("sorted %v", ints)
t.Errorf(" got %v", data)
}
}
func TestSortFuncIntSlice(t *testing.T) {
data := Clone(ints[:])
SortFunc(data, func(a, b int) int { return a - b })
if !IsSorted(data) {
t.Errorf("sorted %v", ints)
t.Errorf(" got %v", data)
}
}
func TestSortFloat64Slice(t *testing.T) {
data := Clone(float64s[:])
Sort(data)
if !IsSorted(data) {
t.Errorf("sorted %v", float64s)
t.Errorf(" got %v", data)
}
}
func TestSortFloat64SliceWithNaNs(t *testing.T) {
data := float64sWithNaNs[:]
data2 := Clone(data)
Sort(data)
sort.Float64s(data2)
if !IsSorted(data) {
t.Error("IsSorted indicates data isn't sorted")
}
// Compare for equality using cmp.Compare, which considers NaNs equal.
if !EqualFunc(data, data2, func(a, b float64) bool { return cmp.Compare(a, b) == 0 }) {
t.Errorf("mismatch between Sort and sort.Float64: got %v, want %v", data, data2)
}
}
func TestSortStringSlice(t *testing.T) {
data := Clone(strs[:])
Sort(data)
if !IsSorted(data) {
t.Errorf("sorted %v", strs)
t.Errorf(" got %v", data)
}
}
func TestSortLarge_Random(t *testing.T) {
n := 1000000
if testing.Short() {
n /= 100
}
data := make([]int, n)
for i := 0; i < len(data); i++ {
data[i] = rand.Intn(100)
}
if IsSorted(data) {
t.Fatalf("terrible rand.rand")
}
Sort(data)
if !IsSorted(data) {
t.Errorf("sort didn't sort - 1M ints")
}
}
type intPair struct {
a, b int
}
type intPairs []intPair
// Pairs compare on a only.
func intPairCmp(x, y intPair) int {
return x.a - y.a
}
// Record initial order in B.
func (d intPairs) initB() {
for i := range d {
d[i].b = i
}
}
// InOrder checks if a-equal elements were not reordered.
func (d intPairs) inOrder() bool {
lastA, lastB := -1, 0
for i := 0; i < len(d); i++ {
if lastA != d[i].a {
lastA = d[i].a
lastB = d[i].b
continue
}
if d[i].b <= lastB {
return false
}
lastB = d[i].b
}
return true
}
func TestStability(t *testing.T) {
n, m := 100000, 1000
if testing.Short() {
n, m = 1000, 100
}
data := make(intPairs, n)
// random distribution
for i := 0; i < len(data); i++ {
data[i].a = rand.Intn(m)
}
if IsSortedFunc(data, intPairCmp) {
t.Fatalf("terrible rand.rand")
}
data.initB()
SortStableFunc(data, intPairCmp)
if !IsSortedFunc(data, intPairCmp) {
t.Errorf("Stable didn't sort %d ints", n)
}
if !data.inOrder() {
t.Errorf("Stable wasn't stable on %d ints", n)
}
// already sorted
data.initB()
SortStableFunc(data, intPairCmp)
if !IsSortedFunc(data, intPairCmp) {
t.Errorf("Stable shuffled sorted %d ints (order)", n)
}
if !data.inOrder() {
t.Errorf("Stable shuffled sorted %d ints (stability)", n)
}
// sorted reversed
for i := 0; i < len(data); i++ {
data[i].a = len(data) - i
}
data.initB()
SortStableFunc(data, intPairCmp)
if !IsSortedFunc(data, intPairCmp) {
t.Errorf("Stable didn't sort %d ints", n)
}
if !data.inOrder() {
t.Errorf("Stable wasn't stable on %d ints", n)
}
}
type S struct {
a int
b string
}
func cmpS(s1, s2 S) int {
return cmp.Compare(s1.a, s2.a)
}
func TestMinMax(t *testing.T) {
intCmp := func(a, b int) int { return a - b }
tests := []struct {
data []int
wantMin int
wantMax int
}{
{[]int{7}, 7, 7},
{[]int{1, 2}, 1, 2},
{[]int{2, 1}, 1, 2},
{[]int{1, 2, 3}, 1, 3},
{[]int{3, 2, 1}, 1, 3},
{[]int{2, 1, 3}, 1, 3},
{[]int{2, 2, 3}, 2, 3},
{[]int{3, 2, 3}, 2, 3},
{[]int{0, 2, -9}, -9, 2},
}
for _, tt := range tests {
t.Run(fmt.Sprintf("%v", tt.data), func(t *testing.T) {
gotMin := Min(tt.data)
if gotMin != tt.wantMin {
t.Errorf("Min got %v, want %v", gotMin, tt.wantMin)
}
gotMinFunc := MinFunc(tt.data, intCmp)
if gotMinFunc != tt.wantMin {
t.Errorf("MinFunc got %v, want %v", gotMinFunc, tt.wantMin)
}
gotMax := Max(tt.data)
if gotMax != tt.wantMax {
t.Errorf("Max got %v, want %v", gotMax, tt.wantMax)
}
gotMaxFunc := MaxFunc(tt.data, intCmp)
if gotMaxFunc != tt.wantMax {
t.Errorf("MaxFunc got %v, want %v", gotMaxFunc, tt.wantMax)
}
})
}
svals := []S{
{1, "a"},
{2, "a"},
{1, "b"},
{2, "b"},
}
gotMin := MinFunc(svals, cmpS)
wantMin := S{1, "a"}
if gotMin != wantMin {
t.Errorf("MinFunc(%v) = %v, want %v", svals, gotMin, wantMin)
}
gotMax := MaxFunc(svals, cmpS)
wantMax := S{2, "a"}
if gotMax != wantMax {
t.Errorf("MaxFunc(%v) = %v, want %v", svals, gotMax, wantMax)
}
}
func TestMinMaxNaNs(t *testing.T) {
fs := []float64{1.0, 999.9, 3.14, -400.4, -5.14}
if Min(fs) != -400.4 {
t.Errorf("got min %v, want -400.4", Min(fs))
}
if Max(fs) != 999.9 {
t.Errorf("got max %v, want 999.9", Max(fs))
}
// No matter which element of fs is replaced with a NaN, both Min and Max
// should propagate the NaN to their output.
for i := 0; i < len(fs); i++ {
testfs := Clone(fs)
testfs[i] = math.NaN()
fmin := Min(testfs)
if !math.IsNaN(fmin) {
t.Errorf("got min %v, want NaN", fmin)
}
fmax := Max(testfs)
if !math.IsNaN(fmax) {
t.Errorf("got max %v, want NaN", fmax)
}
}
}
func TestMinMaxPanics(t *testing.T) {
intCmp := func(a, b int) int { return a - b }
emptySlice := []int{}
if !panics(func() { Min(emptySlice) }) {
t.Errorf("Min([]): got no panic, want panic")
}
if !panics(func() { Max(emptySlice) }) {
t.Errorf("Max([]): got no panic, want panic")
}
if !panics(func() { MinFunc(emptySlice, intCmp) }) {
t.Errorf("MinFunc([]): got no panic, want panic")
}
if !panics(func() { MaxFunc(emptySlice, intCmp) }) {
t.Errorf("MaxFunc([]): got no panic, want panic")
}
}
func TestBinarySearch(t *testing.T) {
str1 := []string{"foo"}
str2 := []string{"ab", "ca"}
str3 := []string{"mo", "qo", "vo"}
str4 := []string{"ab", "ad", "ca", "xy"}
// slice with repeating elements
strRepeats := []string{"ba", "ca", "da", "da", "da", "ka", "ma", "ma", "ta"}
// slice with all element equal
strSame := []string{"xx", "xx", "xx"}
tests := []struct {
data []string
target string
wantPos int
wantFound bool
}{
{[]string{}, "foo", 0, false},
{[]string{}, "", 0, false},
{str1, "foo", 0, true},
{str1, "bar", 0, false},
{str1, "zx", 1, false},
{str2, "aa", 0, false},
{str2, "ab", 0, true},
{str2, "ad", 1, false},
{str2, "ca", 1, true},
{str2, "ra", 2, false},
{str3, "bb", 0, false},
{str3, "mo", 0, true},
{str3, "nb", 1, false},
{str3, "qo", 1, true},
{str3, "tr", 2, false},
{str3, "vo", 2, true},
{str3, "xr", 3, false},
{str4, "aa", 0, false},
{str4, "ab", 0, true},
{str4, "ac", 1, false},
{str4, "ad", 1, true},
{str4, "ax", 2, false},
{str4, "ca", 2, true},
{str4, "cc", 3, false},
{str4, "dd", 3, false},
{str4, "xy", 3, true},
{str4, "zz", 4, false},
{strRepeats, "da", 2, true},
{strRepeats, "db", 5, false},
{strRepeats, "ma", 6, true},
{strRepeats, "mb", 8, false},
{strSame, "xx", 0, true},
{strSame, "ab", 0, false},
{strSame, "zz", 3, false},
}
for _, tt := range tests {
t.Run(tt.target, func(t *testing.T) {
{
pos, found := BinarySearch(tt.data, tt.target)
if pos != tt.wantPos || found != tt.wantFound {
t.Errorf("BinarySearch got (%v, %v), want (%v, %v)", pos, found, tt.wantPos, tt.wantFound)
}
}
{
pos, found := BinarySearchFunc(tt.data, tt.target, strings.Compare)
if pos != tt.wantPos || found != tt.wantFound {
t.Errorf("BinarySearchFunc got (%v, %v), want (%v, %v)", pos, found, tt.wantPos, tt.wantFound)
}
}
})
}
}
func TestBinarySearchInts(t *testing.T) {
data := []int{20, 30, 40, 50, 60, 70, 80, 90}
tests := []struct {
target int
wantPos int
wantFound bool
}{
{20, 0, true},
{23, 1, false},
{43, 3, false},
{80, 6, true},
}
for _, tt := range tests {
t.Run(strconv.Itoa(tt.target), func(t *testing.T) {
{
pos, found := BinarySearch(data, tt.target)
if pos != tt.wantPos || found != tt.wantFound {
t.Errorf("BinarySearch got (%v, %v), want (%v, %v)", pos, found, tt.wantPos, tt.wantFound)
}
}
{
cmp := func(a, b int) int {
return a - b
}
pos, found := BinarySearchFunc(data, tt.target, cmp)
if pos != tt.wantPos || found != tt.wantFound {
t.Errorf("BinarySearchFunc got (%v, %v), want (%v, %v)", pos, found, tt.wantPos, tt.wantFound)
}
}
})
}
}
func TestBinarySearchFloats(t *testing.T) {
data := []float64{math.NaN(), -0.25, 0.0, 1.4}
tests := []struct {
target float64
wantPos int
wantFound bool
}{
{math.NaN(), 0, true},
{math.Inf(-1), 1, false},
{-0.25, 1, true},
{0.0, 2, true},
{1.4, 3, true},
{1.5, 4, false},
}
for _, tt := range tests {
t.Run(fmt.Sprintf("%v", tt.target), func(t *testing.T) {
{
pos, found := BinarySearch(data, tt.target)
if pos != tt.wantPos || found != tt.wantFound {
t.Errorf("BinarySearch got (%v, %v), want (%v, %v)", pos, found, tt.wantPos, tt.wantFound)
}
}
})
}
}
func TestBinarySearchFunc(t *testing.T) {
data := []int{1, 10, 11, 2} // sorted lexicographically
cmp := func(a int, b string) int {
return strings.Compare(strconv.Itoa(a), b)
}
pos, found := BinarySearchFunc(data, "2", cmp)
if pos != 3 || !found {
t.Errorf("BinarySearchFunc(%v, %q, cmp) = %v, %v, want %v, %v", data, "2", pos, found, 3, true)
}
}