Q2: Polynomials using a linked list

• Please design a linked list structure for polynomials in C. • Please calculate the result of adding two polynomials, A(X) and B(X), together. The exponents of the polynomials must match for coefficients to be added.

題目說明二

請設計C語言程式,以此串列的結構 求出以下兩多項式A(X)+B(X)的最終結果。 • A=3X3+4X + 2 B = 6X3+ 8X² + 6X + 9

My Code:

not the most efficient code i would say：

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

// Define the EquationA structure
struct EquationA {
    int X_power;
    int alpha;
    struct EquationA* next;
};

// Define the EquationB structure
struct EquationB {
    int X_power;
    int alpha;
    struct EquationB* next;
};
struct EquationC {
    int X_power;
    int alpha;
    struct EquationC* next;
};

// Initialize the start pointers for both linked lists
struct EquationA* startA = NULL;
struct EquationB* startB = NULL;
struct EquationC* startC = NULL;

void invertEquationA() {
    struct EquationA* current = startA;
    struct EquationA* previous = NULL;
    struct EquationA* next = NULL;

    while (current != NULL) {
        next = current->next; // Store the next node
        current->next = previous; // Change the next of the current node

        // Move pointers one position ahead
        previous = current;
        current = next;
    }

    startA = previous; // Update the start to the last node
}

void invertEquationB() {
    struct EquationB* current = startB;
    struct EquationB* previous = NULL;
    struct EquationB* next = NULL;

    while (current != NULL) {
        next = current->next; // Store the next node
        current->next = previous; // Change the next of the current node

        // Move pointers one position ahead
        previous = current;
        current = next;
    }

    startB = previous; // Update the start to the last node
}

void invertEquationC() {
    struct EquationC* current = startC;
    struct EquationC* previous = NULL;
    struct EquationC* next = NULL;

    while (current != NULL) {
        next = current->next; // Store the next node
        current->next = previous; // Change the next of the current node

        // Move pointers one position ahead
        previous = current;
        current = next;
    }

    startC = previous; // Update the start to the last node
}

// Function to add an equation to the first linked list (EquationA)
void addEquationA() {
    struct EquationA* eqnA = (struct EquationA*)malloc(sizeof(struct EquationA));
    if (eqnA == NULL) {
        printf("Memory allocation failed.\\n");
        return;
    }

    printf("Enter X_power for EquationA: ");
    scanf("%d", &eqnA->X_power);
    printf("Enter Alpha for EquationA: ");
    scanf("%d", &eqnA->alpha);

    eqnA->next = startA;
    startA = eqnA;
    printf("EquationA added successfully.\\n");
}

// Function to add an equation to the second linked list (EquationB)
void addEquationB() {
    struct EquationB* eqnB = (struct EquationB*)malloc(sizeof(struct EquationB));
    if (eqnB == NULL) {
        printf("Memory allocation failed.\\n");
        return;
    }

    printf("Enter X_power for EquationB: ");
    scanf("%d", &eqnB->X_power);
    printf("Enter Alpha for EquationB: ");
    scanf("%d", &eqnB->alpha);

    eqnB->next = startB;
    startB = eqnB;
    printf("EquationB added successfully.\\n");
}

// Function to list the equations in the first linked list (EquationA)
void listEquationA() {
    struct EquationA* current = startA;
    if (current == NULL) {
        printf("No data found in EquationA.\\n");
        return;
    }

    while (current != NULL) {
    	if(current == startA){
    		printf("A=%dX^%d ", current->alpha, current->X_power);
		}
    	if(current != startA and current->X_power != 0){
    		printf(" + %dX^%d ", current->alpha, current->X_power);
		}
		if(current->X_power == 0){
    		printf(" + %d \\n", current->alpha);
		}
        current = current->next;
    }
}

// Function to list the equations in the second linked list (EquationB)
void listEquationB() {
    struct EquationB* current = startB;
    if (current == NULL) {
        printf("No data found in EquationB.\\n");
        return;
    }

    while (current != NULL) {
    	if(current == startB){
    		printf("B=%dX^%d ", current->alpha, current->X_power);
		}
    	if(current != startB and current->X_power != 0){
    		printf(" + %dX^%d ", current->alpha, current->X_power);
		}
		if(current->X_power == 0){
    		printf(" + %d \\n", current->alpha);
		}
        current = current->next;
    }
}

void listEquationC() {
    struct EquationC* current = startC;
    if (current == NULL) {
        printf("No data found in EquationC.\\n");
        return;
    }

    while (current != NULL) {
    	if(current == startC){
    		printf("C=%dX^%d ", current->alpha, current->X_power);
		}
    	if(current != startC and current->X_power != 0){
    		printf(" + %dX^%d ", current->alpha, current->X_power);
		}
		if(current->X_power == 0){
    		printf(" + %d \\n", current->alpha);
		}
        current = current->next;
    }
}

void addEquationC() {
    struct EquationA* currentA = startA;
    struct EquationB* currentB = startB;

    while (currentA != NULL || currentB != NULL) {
        struct EquationC* currentC = (struct EquationC*)malloc(sizeof(struct EquationC));
        if (currentC == NULL) {
            printf("Memory allocation failed for EquationC.\\n");
            return;
        }

        currentC->alpha = 0;
        currentC->X_power = 0;

        if (currentA != NULL && currentB != NULL) {
            if (currentA->X_power == currentB->X_power) {
                currentC->X_power = currentA->X_power;
                currentC->alpha = currentA->alpha + currentB->alpha;
                currentA = currentA->next;
                currentB = currentB->next;
            } else if (currentA->X_power > currentB->X_power) {
                currentC->X_power = currentA->X_power;
                currentC->alpha = currentA->alpha;
                currentA = currentA->next;
            } else {
                currentC->X_power = currentB->X_power;
                currentC->alpha = currentB->alpha;
                currentB = currentB->next;
            }
        } else if (currentA != NULL) {
            currentC->X_power = currentA->X_power;
            currentC->alpha = currentA->alpha;
            currentA = currentA->next;
        } else if (currentB != NULL) {
            currentC->X_power = currentB->X_power;
            currentC->alpha = currentB->alpha;
            currentB = currentB->next;
        }

        if (currentC->alpha != 0) {
            currentC->next = startC;
            startC = currentC;
        } else {
            free(currentC);
        }
    }
}

	
	

int main() {
    for (int i = 1; i <= 3; i++) {
    addEquationA();
}
    for (int i = 1; i <= 4; i++) {
    addEquationB();
}    
invertEquationA();
invertEquationB(); 
listEquationA();
    listEquationB();
    addEquationC(); 
    invertEquationC();
    listEquationC();

    return 0;
}