so this is a simple c programming using recursion which returns the power of the input value, but for some reason it showing error

#include <iostream>
//int sum = 1;

int powerOfNumber(int n, int p) {
    if (n != 0) {
        p--; 
        return powerOfNumber(n , p) * n;
    }
    if (n == 0) {
        return 1;
    }
}


int main()
{
    std::cout <<powerOfNumber(5, 2);
   

    return 0;
    
}

CodePudding user response：

Your stop condition must be in terms of p, not n, because that's the variable you are substracting the value, either way you could substract the value of n

CodePudding user response：

#include <iostream>

using namespace std; 

int powerOfNumber(int n, int p) {
    if(p==0)
        return 1;
    else 
        return (n*powerOfNumber(n,p-1));     
}


int main()
{
    std::cout <<powerOfNumber(5, 2);

    return 0;
}

Your powerOfNumber function never terminates because n is always 5.

CodePudding user response：

You have a bug that the condition needed to be

    if (p != 0) {
    ...
    }
    if ( p == 0)
        return 0;

rather than if (n != 0) { ... } if ( n == 0) ....

But you might still get the same warning though if the compiler couldn't deduce that there'll be always be a return.

You could simply rewrite it to:

int powerOfNumber(int n, int p) {
   if (p != 0) {
       p--; 
       return powerOfNumber(n , p) * n;
   }

   return 1;
}

so that there's always a return statement unconditionally.

P.S.: Be aware that if you are using a large input for either n or p, you might run to integer overflow.