配列の総和
/*
template<class _InIt, class _Ty>
_Ty accumulate(_InIt _First, _InIt _Last, _Ty _Val)
template<class _InIt, class _Ty, class _Fn2>
_Ty _Accumulate(_InIt _First, _InIt _Last, _Ty _Val, _Fn2 _Func)
*/
#include <numeric>
#include <functional>
#include <iostream>
using namespace std;
int main()
{
int a[] = {1,4,9};
// 0+1+4+9 = 14
cout << accumulate( a, a+3, 0 ) << endl;
// 1*1*4*9 = 36
cout << accumulate( a, a+3, 1, multiplies<int>() ) << endl;
return 0;
}
