计算方法之迭代法求方程根

/************************
* 用迭代法求方程
* f(x)=e^(-x)-x+1=0
* 的根
*************************/
#include<stdio.h>
#include<math.h>
#include<conio.h>float fa(float);
float dd(float);
int main() {float x0;printf("input data x0 = ");scanf("%f", &x0);printf("The root of f(x) = 0  is x = \t%f\n", dd(x0));return 0;
}
float dd(float a) {float x, x0, e;int i;printf("input eps = ");scanf("%f", &e);x0 = a;printf("x0 = %f\n", x0);for (i = 1;; i++) {x = fa(x0);printf("x(%d)=%f\n", i, x);if (fabs(x - x0) < e)return x;elsex0 = x;}
}
float f(float x) {float a;a = exp(-x) - x + 1;return a;
}
float fa(float x) {float a;a = exp(-x) + 1;return a;
}