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

const char * OPER_NAMES[] = { "x", "sin(x)", "cos(x)", "log(x)", "exp(x)", NULL };

double identite(double x)
{
    return x;
}

double erreur(double x)
{
    printf("erreur\n");
    return 0;
}

double (*OPER_FN [])(double) = { identite, sin, cos, log, exp, erreur };

typedef enum ope {
  ID , SIN, COS, LOG, EXP, NONE
} OP;

int identification(char chaine[])
{
    OP operation = ID;
    while ( OPER_NAMES[operation] && strcmp(chaine,OPER_NAMES[operation]) )
    {
        operation++;
    }
    return operation;
}

double evaln(double d, OP operation)
{
    double resultat;
    switch (operation)
    {
        case ID:
            resultat = d;
            break;
        case SIN:
            resultat = sin(d);
            break;
        case COS:
            resultat = cos(d);
            break;
        case LOG:
            resultat = log(d);
            break;
        case EXP:
            resultat = exp(d);
            break;
        default:
            break;
    }
    return resultat;
}

double evalp(double d, OP operation)
{
    return OPER_FN[operation](d);
}

void calcul(float a, float b, float d, OP operation)
{
    double i;
    for (i = a; i <= b; i = i + d )
    {
        printf("%f\n", evalp(i, operation));
    }
}




int main()
{
    printf("%f\n",evalp(0, COS));
    char operation[255];
    float a, b, d;
    printf("veuillez saisir l'opération\n");
    scanf("%s", operation);
    OP op = identification(operation);

    printf("veuillez saisir l'intervalle et le pas\n");
    scanf("%f %f %f", &a, &b, &d);


    calcul(a, b, d, op);
    return 0;
}