Merge pull request #1179 from 0xff-dev/1093

Add solution and test-cases for problem 1093

Author: 6boris

leetcode/1001-1100/1093.Statistics-from-a-Large-Sample/README.md

@@ -1,28 +1,45 @@
 # [1093.Statistics from a Large Sample][title]
 
-> [!WARNING|style:flat]
-> This question is temporarily unanswered if you have good ideas. Welcome to [Create Pull Request PR](https://github.com/kylesliu/awesome-golang-algorithm)
-
 ## Description
+You are given a large sample of integers in the range `[0, 255]`. Since the sample is so large, it is represented by an array `count` where `count[k]` is the **number of times** that `k` appears in the sample.
+
+Calculate the following statistics:
+
+- `minimum`: The minimum element in the sample.
+- `maximum`: The maximum element in the sample.
+- `mean`: The average of the sample, calculated as the total sum of all elements divided by the total number of elements.
+- `median`:
+
+    - If the sample has an odd number of elements, then the `median` is the middle element once the sample is sorted.
+    - If the sample has an even number of elements, then the `median` is the average of the two middle elements once the sample is sorted.
+
+- `mode`: The number that appears the most in the sample. It is guaranteed to be **unique**.
+
+Return the statistics of the sample as an array of floating-point numbers `[minimum, maximum, mean, median, mode]`. Answers within `10^-5` of the actual answer will be accepted.
 
 **Example 1:**
 
 ```
-Input: a = "11", b = "1"
-Output: "100"
+Input: count = [0,1,3,4,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
+Output: [1.00000,3.00000,2.37500,2.50000,3.00000]
+Explanation: The sample represented by count is [1,2,2,2,3,3,3,3].
+The minimum and maximum are 1 and 3 respectively.
+The mean is (1+2+2+2+3+3+3+3) / 8 = 19 / 8 = 2.375.
+Since the size of the sample is even, the median is the average of the two middle elements 2 and 3, which is 2.5.
+The mode is 3 as it appears the most in the sample.
 ```
 
-## 题意
-> ...
-
-## 题解
+**Example 3:**
 
-### 思路1
-> ...
-Statistics from a Large Sample
-```go
 ```
-
+Input: count = [0,4,3,2,2,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0]
+Output: [1.00000,4.00000,2.18182,2.00000,1.00000]
+Explanation: The sample represented by count is [1,1,1,1,2,2,2,3,3,4,4].
+The minimum and maximum are 1 and 4 respectively.
+The mean is (1+1+1+1+2+2+2+3+3+4+4) / 11 = 24 / 11 = 2.18181818... (for display purposes, the output shows the rounded number 2.18182).
+Since the size of the sample is odd, the median is the middle element 2.
+The mode is 1 as it appears the most in the sample.
+```
 
 ## 结语
 

leetcode/1001-1100/1093.Statistics-from-a-Large-Sample/Solution.go

@@ -1,5 +1,62 @@
 package Solution
 
-func Solution(x bool) bool {
-	return x
+func Solution(count []int) []float64 {
+	var _max, _min, _mode, _modeCount int
+	_min = -1
+	total := int64(0)
+	sum := int64(0)
+
+	for i, c := range count {
+		if c == 0 {
+			continue
+		}
+		sum += int64(i) * int64(c)
+		total += int64(c)
+
+		_max = max(_max, i)
+		if _min == -1 || _min > i {
+			_min = i
+		}
+		if c > _modeCount {
+			_modeCount = c
+			_mode = i
+		}
+	}
+	_avg := float64(sum) / float64(total)
+	var a float64
+	start := total / 2
+	if total&1 == 0 {
+		start--
+	}
+	used := int64(0)
+	justSelected := false
+	for i, c := range count {
+		if c == 0 {
+			continue
+		}
+		if justSelected {
+			a += float64(i)
+			a /= 2
+			break
+		}
+		next := used + int64(c)
+		if next-1 < start {
+			used = next
+			continue
+		}
+
+		diff := next - start
+		a += float64(i)
+		if total&1 == 1 {
+			break
+		}
+		if diff >= 2 {
+			a += a
+			a /= 2
+			break
+		}
+		justSelected = true
+	}
+
+	return []float64{float64(_min), float64(_max), _avg, a, float64(_mode)}
 }

leetcode/1001-1100/1093.Statistics-from-a-Large-Sample/Solution_test.go

@@ -1,39 +1,51 @@
 package Solution
 
 import (
-	"reflect"
+	"math"
 	"strconv"
 	"testing"
 )
 
+const (
+	epsilon = 1e-5
+)
+
+func checkDiff(a, b []float64) bool {
+	for i := range a {
+		if !(math.Abs(a[i]-b[i]) < epsilon) {
+			return false
+		}
+	}
+	return true
+}
+
 func TestSolution(t *testing.T) {
 	//	测试用例
 	cases := []struct {
 		name   string
-		inputs bool
-		expect bool
+		inputs []int
+		expect []float64
 	}{
-		{"TestCase", true, true},
-		{"TestCase", true, true},
-		{"TestCase", false, false},
+		{"TestCase1", []int{0, 1, 3, 4, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, []float64{1.00000, 3.00000, 2.37500, 2.50000, 3.00000}},
+		{"TestCase2", []int{0, 4, 3, 2, 2, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}, []float64{1.00000, 4.00000, 2.18182, 2.00000, 1.00000}},
 	}
 
 	//	开始测试
 	for i, c := range cases {
 		t.Run(c.name+" "+strconv.Itoa(i), func(t *testing.T) {
 			got := Solution(c.inputs)
-			if !reflect.DeepEqual(got, c.expect) {
+			if !checkDiff(got, c.expect) {
 				t.Fatalf("expected: %v, but got: %v, with inputs: %v",
 					c.expect, got, c.inputs)
 			}
 		})
 	}
 }
 
-//	压力测试
+// 压力测试
 func BenchmarkSolution(b *testing.B) {
 }
 
-//	使用案列
+// 使用案列
 func ExampleSolution() {
 }