Question

In C++

Problem: As usual, Wario is concerned about nothing other than acquiring more money. In order to maximize profits, Wario needs to use calculus to create derivatives for analysis. Unfortunately, Wario never took calculus; there wasn’t much need of it in the Mushroom Kingdom. So, Wario is calling on you to help him by creating a program to create derivatives.

Answer 1

#include <bits/stdc++.h>
using namespace std;
  
long long warioderivative(string polynomialTerm, long long coefficientval)
{
string coeffStr = "";
int i;
for (i = 0; polynomialTerm[i] != 'x'; i++)
{
coeffStr.push_back(polynomialTerm[i]);
}
  
long long coeff = atol(coeffStr.c_str());
// Get Power (Skip 2 characters for x and ^)
string powStr = "";
for (i = i + 2; i != polynomialTerm.size(); i++)
{
powStr.push_back(polynomialTerm[i]);
}
long long power = atol(powStr.c_str());
  
// For ax^n, we return a(n)x^(n-1)
if(coeff==0) // coefficient is 1 this coeff will zero
{
coeff=1;
}
return coeff * power * pow(coefficientval, power - 1);
}
  
long long derivativeVal(string& poly, int val)
{
long long ans = 0;
  
// We use istringstream to get input in tokens
istringstream is(poly);
  
string pTerm;
while (is >> pTerm) {
// If the token is equal to '+' then continue with the string
if (pTerm == "+")
continue;
// Otherwise find the derivative of that
// particular term
else
ans = (ans + warioderivative(pTerm, val));
}
return ans;
}
int main()
{
string str = "2x^3 + 10x^1 + x^2";
int val = 5;
cout << derivativeVal(str, val);
return 0;
}

/* output:- 170

***************************

derivative of 2x^3 + 10x^1 +x^2 is

6x^2 + 10 + 2x^1

putting x=5

6*25 + 10 + 2*5

170

*/