要求精度为10^-8分别用dowhile、while、和for语句编写程序：-1^n+1x^nn!累加

使用do...while语句：

#include <stdio.h>

int main() { int n = 1; double x, sum = 0, term = 1; printf("请输入x的值："); scanf("%lf", &x); do { sum += term; n++; term *= (-1) * x / n; } while (term >= 1e-8 || term <= -1e-8); printf("当精度为10^-8时，(-1)^(n+1)*x^n/n!的累加和为：%lf", sum); return 0; }

使用while语句：

#include <stdio.h>

int main() { int n = 1; double x, sum = 0, term = 1; printf("请输入x的值："); scanf("%lf", &x); while (term >= 1e-8 || term <= -1e-8) { sum += term; n++; term *= (-1) * x / n; } printf("当精度为10^-8时，(-1)^(n+1)*x^n/n!的累加和为：%lf", sum); return 0; }

使用for语句：

#include <stdio.h>

int main() { int n; double x, sum = 0, term = 1; printf("请输入x的值："); scanf("%lf", &x); for (n = 1; term >= 1e-8 || term <= -1e-8; n++) { sum += term; term *= (-1) * x / n; } printf("当精度为10^-8时，(-1)^(n+1)*x^n/n!的累加和为：%lf", sum); return 0;