c++ - 总和不会在此数组类型代码中正确打印出来

Question

#include<iostream>
#include<fstream>

using namespace std;

int main()
{
    ifstream inFile;
    ofstream outFile;
    int sum;
    double average;
    int apple[50];
    int b1;
    int i;

    outFile.open("apple_trip.txt");

    for (i = 0; i < 50; i++)
    {
        b1 = rand() % 100;
        outFile << b1 << endl;
    }

    outFile.close();

    inFile.open("apple_trip.txt");
    for (i = 0; i < 50; i++)   // This loop ensures you don't keep overwriting
        // the same value, which would be off by 1
    {
        inFile >> apple[i];
    }

    for (i = 0; i < 50; i++) // The loop variable is i, not apple[i], and we stop at 50
    {
        if (apple[i] < 25)
        {
            cout << apple[i] << " people picked less than 25 apples" << endl;
        }
    }

    for (i = 0; i < 50; i++)
    {
        if (apple[i] > 80 && apple[i] < 100) // change < to >
        {
            cout << "The number of apples that is between 80 and 100 is : " << apple[i] << endl;
        }

    }

    for (i = 0; i < 50; i++)
    {
        sum = 0;
        sum += apple[i];
        average = sum / 50.0;
        cout << average;
    }
    return 0;
}

基本上最后一个 for 循环不会正确打印出总和。它给出了一些奇怪的小数点。一直试图找出错误所在，但我只是 C++ 的初学者，而且我在计算机科学方面并不是很聪明。任何帮助将不胜感激!

Answer 1

for (i = 0; i < 50; i++)
{
    sum = 0;
    sum += apple[i];
    average = sum / 50.0;
    cout << average;
}

是的，这不会计算平均值。您必须在循环外初始化 sum 并打印 average。

试试这个:

sum = 0;
for (i = 0; i < 50; i++)
{
    sum += apple[i];
}
average = sum / 50.0;
cout << average;

average = sum/50.0; 可以在循环内部或外部，但在外部更好。