yr

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

float f(float);     //  Function
float ff(float);    //1st Derivative
float fff(float);   //2nd Derivative
float dih(void);
float hor(void);
float nut(void);

bool err=false;
bool steps=true;    //turn on/off steps

int main() {
    int x; float z;
    while(true) {
        printf("exp(x)+x=0\n1: Dihotomii\n2: Hord\n3: Newton\n0: Exit\n");
        scanf("%d",&x);
        switch(x) {
        case 0: return 0;
        case 1: z=dih(); break;
        case 2: z=hor(); break;
        case 3: z=nut(); break;
        default: break;
        }
        if(!err) printf("Koren' yravneniya: x=%.10f\n\n",z); else err=true;
    }
}

float f(float x) {
    return exp(x)+x;
}

float ff(float x,float dx) {
    //float dx=0.0001;
    return (f(x+dx)-f(x))/dx;
}

float fff(float x,float dx) {
    return (f(x+dx)-2*f(x)+f(x-dx))/(dx*dx);
}

float hor() {
    float a,b,c,d,e;
    printf("Vvedite [a,b], eps, delta:\n");
    scanf("%f%f%f%f",&a,&b,&e,&d);

    if(f(a)*f(b)>0) {
        printf("Koren ne mozhet bit' naiden na etom promezhytke etim metodom\n");
        err=true;
        return 0;
    }

    while(true) {
        c=a+fabs(f(a)/(f(b)-f(a)))*(b-a);
        if(steps) printf("x=%.10f\n",c);
        if(((fabs(c-a)<d) && (fabs(f(c))<e))) break;
        if(f(c)*f(a)>0) a=c; else b=c;
    }
    return c;
}

float dih() {
    float a,b,c,d,e;
    printf("Vvedite [a,b], eps, delta:\n");
    scanf("%f%f%f%f",&a,&b,&e,&d);

    if(f(a)*f(b)>0) {
        printf("Koren ne mozhet bit' naiden na etom promezhytke etim metodom\n");
        err=true;
        return 0;
    }

    while(true) {
        c=(a+b)/2;
        if(steps) printf("x=%.10f\n",c);
        if(((fabs(c-a)<d) && (fabs(f(c))<e))) break;
        if(f(c)*f(a)>0) a=c; else b=c;
    }
    return c;
}

float nut() {
    float x,xx,d,e;
    printf("Vvedite x0, eps, delta:\n");
    scanf("%f%f%f",&x,&e,&d);

    if(f(x)*fff(x,e)<0) {
        printf("Koren ne mozhet bit' naiden pri etom x0 etim metodom\n");
        err=true;
        return 0;
    }

    while(true) {
        xx=x-f(x)/ff(x,e);
        if(steps) printf("x=%.10f\n",xx);
        if((fabs(xx-x)<d) && (fabs(f(x))<e)) break;
        x=xx;
    }
    return xx;
}