#include <iostream>
using namespace std;

int power(int a, int b); // Subfunction to calculate a^b
int fact(int c); // Subfunction to calculate factorial

int main() {
    
    int x=0;
    
    for(int i=1 ; i<=20 ; i  )
    
    x = fact(i) / power (i,i);  // needs to calculate like [(1! / 1^1)   (2! / 2^2)   (3! / 3^3)   ......   (20! / 20^20) // assigned x and sum it with counter to calculate final result
    
    cout<<x;
    return 0;
}


int power(int a, int b) { // a^b subfunction
    
    unsigned long long int multip=1; // written the biggest type just in case (idk if i need it)
    
    for (int i=1; i<=b; i  ) {
        
        multip*=a;
        
    }
    
    return multip;
}

int fact(int c) { // factorial subfunction
    
    unsigned long long int multip=1;
    
    for (int i=c ; i>=1 ; i--) {
        
        multip*=i;
        
    }
    
    return multip;
}

I tried to calculate [(1! / 1^1) (2! / 2^2) ... (20! / 20^20)] but somewhy program didn't work at all. output

I'm sorry if the mistake is obvious I've been trying for long hours and can't think much right now. I will return to the replies with fresh head.Have a good day.

CodePudding user response：

You have some serious problems with your types:

int power(...);
int fact(...);

=> this should be long long.

In top of this, you are doing integer division, while you need floating point division:

fact(i) / power (i,i);

... should be:

((double) fact(i)) / power (i,i);

CodePudding user response：

Thank you for your comment. It worked. I changed the subfunctions " int --> unsigned long long " but I didn't understand the reason of making division in "double". What is wrong with doing with decimals? Secondly:

((double) fact(i)) / power (i,i);

why did you only take fact(i) into brackets? Doesn't it need to be like. Has given the same result though:

x = (double) fact(i) / power (i,i);

That's all. Thank you for your help, I appreciate it.