剑指offer 9 双栈实现队列

这道题思路很清晰明了

typedef struct {
    struct stack{
        int data[10000];
        int top;
    }stack[2];
} CQueue;


CQueue* cQueueCreate() {
    CQueue *result = (CQueue*) malloc(sizeof(CQueue));
    result->stack[0].top = -1;
    result->stack[1].top = -1;
    return result;
}

void cQueueAppendTail(CQueue* obj, int value) {
    obj->stack[0].top += 1;
    obj->stack[0].data[obj->stack[0].top] = value;
}

int cQueueDeleteHead(CQueue* obj) {
    if(obj->stack[0].top == -1) return -1;
    while(obj->stack[0].top>0)
    {
        obj->stack[1].top += 1;
        obj->stack[1].data[obj->stack[1].top] = obj->stack[0].data[obj->stack[0].top--];
    }
    int temp = obj->stack[0].data[obj->stack[0].top--];
    while(obj->stack[1].top>-1)
    {
        obj->stack[0].top += 1;
        obj->stack[0].data[obj->stack[0].top] = obj->stack[1].data[obj->stack[1].top--];
    }
    return temp;
}

void cQueueFree(CQueue* obj) {
    free(obj);
}

/**
 * Your CQueue struct will be instantiated and called as such:
 * CQueue* obj = cQueueCreate();
 * cQueueAppendTail(obj, value);
 
 * int param_2 = cQueueDeleteHead(obj);
 
 * cQueueFree(obj);
*/