返回1的阶乘

Question

的情况下返回0我需要的代码的一般解释：

案例1）

在这个阶乘的功能，如果num是0，那么它返回0！这是1？

案例2） 如果number>> = 1，它是return fact，这是它的阶乘值？

据我所知，return 1和return 0都是为了成功生成结果。

那么为什么我不能返回0，在这种情况下？

double factorial(int num) 
    { 
     int fact = 1; 
     int i = 1; 
     if (num == 0) 
      return 1; 
     else 
      while (num >= i) 
      { 
       fact = fact*i; 
       i++; 
      } 
     return fact; 

Answer 1

#include <iostream> 

using namespace std; 

int factorial(int num)    //I changed this to return int since you are taking int and int*int will always be int 
    { 
     int fact = 1;    
     //int i = 1;    //dont need this 
     if (num == 0) 
      return fact;   //You can just say return `fact` or `return 1` - i like to make my code readable - s I used `return fact` 
            //I also prefer to set the value of fact as 1 here and return the 1 at bottom so we only have one return statement 
            //but thats just me - having 2 return statements should be fine if used wisely 

      /*while (num >= i)  //thispart was wrong i reedited it into a better and more efficient code below 
      { 
       fact = fact*i; 
       i++; 
      }*/ 
     else 
      { 
       while(num>1)  // so lets say we enter 4 - 4 is larger than 1 
       { 
       fact*=num;   //first step through it will be fact = fact * num; fact is 1 at first loop so it will be 1 * 4 and we put that value into fact 
       num--;    //here we set num to 3 for next loop and we repeat :D 
       } 
      } 

     return fact;    //here we return the value 
    } 


int main()       //just a normal main 
{ 
    int number; 
    cout<<"Enter number: \n"; 
    cin>>number; 
    cout<<"Factorial of "<<number<<" is "<<factorial(number); 

    return 0; 
} 

我认为你的问题是完全正常的，并是一个初学编程的自己还可以帮助我，当我看到这样的问题。 希望这有助于！祝你好运！