12-10-02.cpp

more efftive 代码

#include <iostream>
#include <numeric>
using namespace std;

int main()
{
  int A1[] = {1, 2, 3};
  int A2[] = {4, 1, -2};
  const int N1 = sizeof(A1) / sizeof(int);
  
  cout << "The inner product of A1 and A2 is "
       << inner_product(A1, A1 + N1, A2, 0)
       << endl;
}