Array product in C++ using STL
In C++, we can quickly find array product using accumulate() and multiplies<>().
The initialProduct specifies the initial value to be considered.
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For multiplication, the initial value is 1.
Eg: array = [5, 10, 15],
So, Product = 1 x 5 x 10 x 15 = 750 (Notice that 1 is the initial value here)
CPP
// C++ program to find array product#include <iostream>#include <numeric>using namespace std;// User defined function that returns product of// arr[] using accumulate() library function.int arrayProduct(int a[], int n){ int initialProduct = 1; return accumulate(a, a + n, initialProduct, multiplies<int>());}int main(){ int a[] = { 5, 10, 15 }; int n = sizeof(a) / sizeof(a[0]); cout << arrayProduct(a, n); return 0;} |
Output:
750
product of vector
CPP
// C++ program to find vector product#include <iostream>#include <numeric>#include <vector>using namespace std;// User defined function that returns product of// v using accumulate() library function.int arrayProduct(vector<int>& v){ int initialProduct = 1; return accumulate(v.begin(), v.end(), initialProduct, multiplies<int>());}int main(){ vector<int> v{ 5, 10, 15 }; cout << arrayProduct(v); return 0;} |
Output:
750
We can also use a custom function in accumulate. Refer numeric header in C++ STL | Set 1 (accumulate() and partial_product()) for details.
