双栈初始化，判断栈空，栈满，出栈用代码实现

双栈初始化、判断栈空、栈满、出栈的代码实现如下：

#define MAXSIZE 100

typedef struct {
    int data[MAXSIZE];
    int top1; // 栈1的栈顶指针
    int top2; // 栈2的栈顶指针
} DoubleStack;

// 双栈初始化
void InitDoubleStack(DoubleStack *S) {
    S->top1 = -1;
    S->top2 = MAXSIZE;
}

// 判断栈1是否为空
int IsEmpty1(DoubleStack *S) {
    return S->top1 == -1;
}

// 判断栈2是否为空
int IsEmpty2(DoubleStack *S) {
    return S->top2 == MAXSIZE;
}

// 判断栈1是否已满
int IsFull1(DoubleStack *S) {
    return S->top1 + 1 == S->top2;
}

// 判断栈2是否已满
int IsFull2(DoubleStack *S) {
    return S->top2 - 1 == S->top1;
}

// 入栈1
void Push1(DoubleStack *S, int x) {
    if (IsFull1(S)) {
        printf("Stack1 is full.\n");
        return;
    }
    S->data[++S->top1] = x;
}

// 入栈2
void Push2(DoubleStack *S, int x) {
    if (IsFull2(S)) {
        printf("Stack2 is full.\n");
        return;
    }
    S->data[--S->top2] = x;
}

// 出栈1
int Pop1(DoubleStack *S) {
    if (IsEmpty1(S)) {
        printf("Stack1 is empty.\n");
        return -1;
    }
    return S->data[S->top1--];
}

// 出栈2
int Pop2(DoubleStack *S) {
    if (IsEmpty2(S)) {
        printf("Stack2 is empty.\n");
        return -1;
    }
    return S->data[S->top2++];
}

注意：以上代码仅供参考，可能存在错误或不足之处，使用时请自行斟酌。