pc2_13b.cpp

来自「《c＋＋大学教程实验指导书》源码」· C++ 代码 · 共 44 行

// Chapter 2 of C++ How to Program
// Programming Challenge 13b (Solution)

#include <iostream>

using std::cout;
using std::cin;
using std::endl;

int main()
{
   double e = 1;
   double factorial;

   // stop at 1 + 1/1! +... + 1/20! 
   for ( int i = 1; i <= 20; i++ ) {  
      factorial = 1;              // reset value of factorial

      for ( int j = i; j > 0; j-- )    // calculate factorial
         factorial *= j;

      e += ( 1.0 / factorial );        // update value of e
   }

   cout << "The value of e is: " << e << endl;

   return 0;

} // end main

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