利用堆栈和队列的性质，通过c语言编写算法函数，实现判断一个字符序列是否是回文，并编写测试主函数进行测试。

算法函数：

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

#define MAX_SIZE 100

typedef struct {
    char data[MAX_SIZE];
    int top;
} Stack;

typedef struct {
    char data[MAX_SIZE];
    int front;
    int rear;
} Queue;

void initStack(Stack *s) {
    s->top = -1;
}

bool isStackEmpty(Stack *s) {
    return s->top == -1;
}

bool isStackFull(Stack *s) {
    return s->top == MAX_SIZE - 1;
}

void push(Stack *s, char c) {
    if (isStackFull(s)) {
        printf("Stack overflow.\n");
        return;
    }
    s->top++;
    s->data[s->top] = c;
}

char pop(Stack *s) {
    if (isStackEmpty(s)) {
        printf("Stack underflow.\n");
        return '\0';
    }
    char c = s->data[s->top];
    s->top--;
    return c;
}

void initQueue(Queue *q) {
    q->front = 0;
    q->rear = -1;
}

bool isQueueEmpty(Queue *q) {
    return q->front > q->rear;
}

bool isQueueFull(Queue *q) {
    return q->rear == MAX_SIZE - 1;
}

void enqueue(Queue *q, char c) {
    if (isQueueFull(q)) {
        printf("Queue overflow.\n");
        return;
    }
    q->rear++;
    q->data[q->rear] = c;
}

char dequeue(Queue *q) {
    if (isQueueEmpty(q)) {
        printf("Queue underflow.\n");
        return '\0';
    }
    char c = q->data[q->front];
    q->front++;
    return c;
}

bool isPalindrome(char *str) {
    Stack s;
    Queue q;
    initStack(&s);
    initQueue(&q);
    int len = strlen(str);
    for (int i = 0; i < len; i++) {
        char c = str[i];
        if (c >= 'A' && c <= 'Z') {
            c += 32;
        }
        if (c >= 'a' && c <= 'z') {
            push(&s, c);
            enqueue(&q, c);
        }
    }
    while (!isStackEmpty(&s) && !isQueueEmpty(&q)) {
        char c1 = pop(&s);
        char c2 = dequeue(&q);
        if (c1 != c2) {
            return false;
        }
    }
    return true;
}

测试主函数：

int main() {
    char str[MAX_SIZE];
    printf("Enter a string: ");
    scanf("%s", str);
    if (isPalindrome(str)) {
        printf("%s is a palindrome.\n", str);
    } else {
        printf("%s is not a palindrome.\n", str);
    }
    return 0;
}