C Programming Code Examples

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Program to Evaluate the given Polynomial Equation

Program to Evaluate the given Polynomial Equation

This C Program evaluates the given polynomial equation. The polynomial equation formula is P(x)=AnXn + An-1Xn-1 + An-2Xn-2+... +A1X + A0.

/*
- C program to evaluate a given polynomial by reading its coefficients
- in an array.
- P(x) = AnXn + An-1Xn-1 + An-2Xn-2+... +A1X + A0
- The polynomial can be written as:
- P(x) = A0 + X(A1 + X(A2 + X(A3 + X(Q4 + X(...X(An-1 + XAn))))
- and evaluated starting from the inner loop
*/

    #include <stdio.h>

    #include <stdlib.h>

    #define maxsize 10

    void main()

    {

        int array[maxsize];

        int j, num, power;

        float x, polySum;

        printf("Enter the order of the polynomial \n");

        scanf("%d", &num);

        printf("Enter the value of x \n");

        scanf("%f", &x);

        /*  Read the coefficients into an array */

        printf("Enter %d coefficients \n", num + 1);

        for (j = 0; j <= num; j++)

        {

            scanf("%d", &array[j]);

        }

        polySum = array[0];

        for (j = 1; j <= num; j++)

        {

            polySum = polySum * x + array[j];

        }

        power = num;

        printf("Given polynomial is: \n");

        for (j = 0; j <= num; j++)

        {

            if (power < 0)

            {

                break;

            }

            /*  printing proper polynomial function */

            if (array[j] > 0)

                printf(" + ");

            else if (array[j] < 0)

                printf(" - ");

            else

                printf(" ");

            printf("%dx^%d  ", abs(array[j]), power--);

        }

        printf("\n Sum of the polynomial = %6.2f \n", polySum);

    }