c++ - 查找点积的函数

Question

我正在尝试填充两个数组，然后使用一个函数来查找点积。有时它会起作用，有时它不会。我不确定这是我填充数组的方式，还是我处理函数的方式。此外，如果我将大小设置为 6 并输入 1、2、3、4、5、6，第一个数组将填充 1、2、3、4、1、2... 它在 4 之后重置。第二个数组已正确填充。 我不知道是否有人可以帮我解决这个问题。

#include <iostream>
using namespace std;

int dotProduct(int* array1, int*array2, int size);

int main() {

    int  size = 0;

    int *array_one = new int[size]{};
    int *array_two = new int[size]{};

    cout << "Please enter array size:" << "\n";
    cin >> size;

    while (size <= 0) { // First while loop, checking array size

        cout << "Please enter array size:" << "\n";
        cin >> size;
    }                 //end of first while loop

    cout << "========= Begin Entering Array Elements =========" 
         << "\n";
    cout << "Array 1: "<< "\n";

    for (int i = 0; i<size; i++){ // Filling up first array, first for 
        loop
            cout << "Enter element number "<< i+1 << ": " ;
        cin >> array_one[i];
    }                               // end or first for loop

    cout <<"=================================================" << 
        "\n";
    cout << "Array 2:" << "\n";

    for (int i = 0; i<size; i++){ // Filling up first array, first for 
        loop
            cout << "Enter element number "<< i+1 << ": " ;
        cin >> array_two[i];
    }

    cout << "The dot product is: " << 
        dotProduct(array_one,array_two,size);
}

int dotProduct(int *arrayUno, int *arrayDos, int size){

    int total = 0;

    for (int i =0; i <= size ; i++ ){
        total = total + (*arrayUno)*(*arrayDos);
        arrayUno++;
        arrayDos++;
    }

    return total;
}

Answer 1

int  size = 0;

int *array_one = new int[size]{};
int *array_two = new int[size]{};

cout << "Please enter array size:" << "\n";
cin >> size;

while (size <= 0) { // First while loop, checking array size

    cout << "Please enter array size:" << "\n";
    cin >> size;
}                 //end of first while loop

在获得大小之前分配数组。你必须先得到尺寸。将此代码更改为:

int size = 0;

cout << "Please enter array size:" << "\n";
cin >> size;

int *array_one = new int[size]{};
int *array_two = new int[size]{};