50 lines
786 B
C
50 lines
786 B
C
|
#include <math.h>
|
||
|
|
#include <stdio.h>
|
||
|
|
|
||
|
|
// Function prototypes
|
||
|
|
double expe(double x);
|
||
|
|
double my_pow(double x, double l);
|
||
|
|
double get_sing(double x, int l);
|
||
|
|
|
||
|
|
int main(void) {
|
||
|
|
// Initial variables
|
||
|
|
double x;
|
||
|
|
scanf("%lf", &x);
|
||
|
|
|
||
|
|
printf("%.4lf\n", expe(x));
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
|
||
|
|
double expe(double x) {
|
||
|
|
double ans = 0;
|
||
|
|
double addup;
|
||
|
|
for (int i = 0;; i++) {
|
||
|
|
addup = (get_sing(x, i));
|
||
|
|
if (fabs(addup) < 1e-8) {
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
ans += addup;
|
||
|
|
}
|
||
|
|
return ans;
|
||
|
|
}
|
||
|
|
|
||
|
|
double my_pow(double x, double l) {
|
||
|
|
double ans = 1;
|
||
|
|
for (long long i = 0; i < l; i++) {
|
||
|
|
ans *= x;
|
||
|
|
}
|
||
|
|
return ans;
|
||
|
|
}
|
||
|
|
|
||
|
|
double get_sing(double x, int l) {
|
||
|
|
if (l <= 0) {
|
||
|
|
return 1;
|
||
|
|
} else {
|
||
|
|
double ans = my_pow(x, l);
|
||
|
|
for (int i = l; i > 1; i--) {
|
||
|
|
ans /= i;
|
||
|
|
}
|
||
|
|
return ans;
|
||
|
|
}
|
||
|
|
}
|