sumstl.cpp

来自「《数据结构、算法与应用》从C++语言应用角度列举了要点」· C++ 代码 · 共 31 行

// sum n numbers using the STL algorithm accumulate
#include <iostream>
// #include <algorithm>
#include <numeric>    // has accumulate

using namespace std;

template<class T>
T sum(T a[], int n)
{// Return sum of the numbers a[0:n-1].
   T theSum = 0;
   return accumulate(a, a+n, theSum);
}

int main()
{
   int a[6] = {1, 2, 3, 4, 5, 6};

   // output the array elements
   cout << "a[0:5] = ";
   copy(a, a+6, ostream_iterator<int>(cout, " "));
   cout << endl;

   // test the function sum
   cout << "sum(a,0) = " << sum(a,0) << endl;
   cout << "sum(a,1) = " << sum(a,1) << endl;
   cout << "sum(a,6) = " << sum(a,6) << endl;
   return 0;
}