正しい平均の出力ができない

~~打ち消し線~~### 前提・実現したいこと

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■■な機能を実装中に以下のエラーメッセージが発生しました。

発生している問題・エラーメッセージ

正しい平均の出力ができない　（2.102e 等になってしまう）

該当のソースコード

C++
1#include<iostream>
2#include<string>
3#include<iomanip>
4using namespace std;
5
6class Arrays {
7	friend ostream &operator<<(ostream&, const Arrays&);
8	friend istream &operator>>(istream&, Arrays&);
9public:
10	Arrays();
11	Arrays operator+(const Arrays& rhs) const;
12	Arrays operator-(const Arrays& rhs) const;
13	Arrays &operator--();
14	Arrays operator--(int);
15	bool operator>(const Arrays& rhs)const;
16	bool operator<=(const Arrays& rhs)const;
17private:
18	int num[10];
19	float avg;
20};
21
22Arrays &Arrays::operator--()
23{
24	for
25		(int i = 0; i < 5; i++)
26	{
27		int t = num[9 - i];
28		num[9 - i] = num[i];
29		num[i] = t;
30	}
31	return *this;
32}
33
34Arrays Arrays::operator--(int)
35{
36	Arrays temp = *this;
37	for
38		(int i = 0; i < 5; i++)
39	{
40		int t = num[9 - i];
41		num[9 - i] = num[i];
42		num[i] = t;
43	}
44	return temp;
45}
46
47Arrays Arrays::operator+(const Arrays& rhs) const
48{
49	Arrays sum;
50	for (int i = 0; i<10; i++)
51	{
52		sum.num[i] = num[i] + rhs.num[i];
53	}
54	return sum;
55}
56
57
58
59Arrays Arrays::operator-(const Arrays& rhs) const
60{
61	Arrays dif;
62	for (int i = 0; i<10; i++)
63	{
64		dif.num[i] = num[i] - rhs.num[i];
65	}
66	return dif;
67}
68
69Arrays::Arrays()
70{
71	int large1 = num[0], large2 = num[0], sum = 0;
72	for (int i = 0; i < 10; i++)
73	{
74		if (num[i] > large1)
75		{
76			large1 = num[i];
77		}
78	}
79	for (int i = 0; i < 10; i++)
80	{
81		if (num[i] < large1 && num[i] > large2)
82		{
83			large2 = num[i];
84		}
85		sum += num[i];
86	}
87	avg = (sum - large1 - large2) / (float)8;
88}
89
90
91
92ostream& operator<<(ostream& output, const Arrays& one)
93{
94	for (int i = 0; i < 10; i++)
95	{
96		output << one.num[i] << ' ';
97	}
98	output << one.avg;
99	return output;
100}
101
102
103istream& operator>>(istream& input, Arrays& one)
104{
105	for (int i = 0; i < 10; i++)
106	{
107		input >> one.num[i];
108	}
109	one.avg;
110	return input;
111}
112
113bool Arrays::operator>(const Arrays& rhs)const
114{
115	return avg > rhs.avg;
116}
117bool Arrays::operator<=(const Arrays& rhs)const
118{
119	return avg <= rhs.avg;
120}
121
122int main()
123{
124	Arrays first, second, sum, dif;
125	cout << "Pick 10 numbers for first the Array ";
126	cin >> first;
127	cout << "Pick 10 numbers for second the Array ";
128	cin >> second;
129	sum = first + second;
130	dif = first - second;
131	cout << endl;
132	cout << "The first Array is " << first << endl;
133	cout << "The second Array is " << second << endl;
134	cout << "The sum of arrays is " << sum << endl;
135	cout << "The difference of arrays is " << dif << endl;
136	cout <<"The reverse first Array: " << --first << endl;
137	cout << "The reverse second Array: "<< --second << endl;
138	cout << "The reverse sum of Array" << --sum << endl;
139	cout << "The reverse difference of Array" << --dif << endl;
140	if (first > second)
141		cout << "the  average  of  the  first  array  with  the  two  largest  values  excluded  from  the  average calculation  is  greater  than  the  average  of  the  second  array  with  the  two  largest  values  excluded  from  the average calculation" << endl;
142	else
143		cout << "  the  average  of  the  first  array  with  the  two  largest  values  excluded  from  the  average calculation is less than or equal to the average of the second array with the two largest values excluded from the average calculation" << endl;
144
145
146	return 0;
147}
148

試したこと

publicでlarge1,large2, sumを宣言
instream で平均計算

補足情報（FW/ツールのバージョンなど）

Visual Studio 2019

求められているのは一番目と二番目に大きい数値を抜いた数列の平均です

行動規範の内容に同意します

回答2件

求められているのは一番目と二番目に大きい数値を抜いた数列の平均です

C++
1#include <algorithm>
2#include <iterator>
3#include <numeric>
4#include <vector>
5#include <iostream>
6
7int main() {
8    int data[] = { 1, 3, 5, 7, 9, 0, 2, 4, 6, 8 };
9    
10    // copyを作る
11    std::vector<int> copy(std::begin(data), std::end(data));
12    // 1, 2 番目に大きい要素を先頭に寄せる
13    auto begin = std::begin(copy);
14    auto end   = std::end(copy);
15    std::iter_swap(begin, std::max_element(begin, end));
16    ++begin;
17    std::iter_swap(begin, std::max_element(begin, end));
18    ++begin;
19    // copy[2..n-1]の総計を要素数で割る
20    double mean = (double)std::reduce(begin, end) / std::distance(begin, end);
21    
22    std::cout << mean << std::endl;
23}

投稿2021/04/25 04:35

episteme

総合スコア16614

※ 回答ではありません

C++
1Arrays::Arrays()
2{
3    int large1 = num[0], large2 = num[0], sum = 0;
4    for (int i = 0; i < 10; i++)
5    {
6        if (num[i] > large1)
7        {
8            large1 = num[i];
9        }
10    }
11    for (int i = 0; i < 10; i++)
12    {
13        if (num[i] < large1 && num[i] > large2)
14        {
15            large2 = num[i];
16        }
17        sum += num[i];
18    }
19    avg = (sum - large1 - large2) / (float)8;
20}