PoissonC

#include <stdio.h>
#include <math.h>

float poisson(float x, float y)
{
    if (y == 0)
        return exp(-x);
    else
    {
        float res = ((float)x / y) * poisson(x, y - 1);
        printf("P(X = %.0f) = %.12f\n", y, res);
        return res;
    }
}

int main()
{
    float x, y;
    printf("Enter the value of lambda and x respectively: \n");
    scanf("%f %f", &x, &y);
    printf("The results for different x are: \n");
    float ans = poisson(x, y);
    return 0;
}