#include <stdio.h> #include <math.h> int main() { double sum = 1; double p_factorial = 1; int max_itr = 20; for (int p = 1; p <= max_itr; p++) { p_factorial *= p; sum += 1/p_factorial; } printf("sum= %.20f\n", sum); printf(" e = %.20f\n", M_E); printf("|sum-e|=%e\n", fabs(sum-M_E)); return 0; }