输入：
输入： Pop PeekMedian Push 3 PeekMedian Push 2 PeekMedian Push 1 PeekMedian Pop Pop Push 5 Push 4 PeekMedian Pop Pop Pop Pop 输出： Invalid Invalid 3 2 2 1 2 4 4 5 3 Invalid#define StackMax 100000 typedef struct stack_array { unsigned int capacity; // 栈的容量 unsigned int top_of_stack; // 栈顶的下标 unsigned int *array; // 用于存放栈的数组 }stack; stack create_stack(unsigned int stack_capacity); void push_stack(stack s, unsigned int data); void pop_stack(stack s); void PeekMedian(stack s); int main() { stack stack = create_stack(StackMax); int topdata, i; } /* 创建一个栈 */ stack *create_stack(unsigned int stack_capacity) { stack *stack = (stack*)malloc(sizeof(stack)); if (stack == NULL) printf("malloc error!\n"); stack->array = (int *)malloc(sizeof(unsigned int) * stack_capacity); if (stack->array == NULL) printf("malloc error!\n"); stack->capacity = stack_capacity; return stack; } /* PUSH 操作 */ void push_stack(stack s, unsigned int data) { if (StackMax <= s->top_of_stack) //栈满 { return; } else { s->array[s->top_of_stack] = data; s->top_of_stack++; } } /* POP 操作 */ void pop_stack(stack s) { if(0 == s->top_of_stack) //栈空 { printf("Invalid\n"); return; } else { s->top_of_stack--; printf("%ld\n",s->array[s->top_of_stack]); } } void PeekMedian(stack s) { unsigned int index = 0; if(0 == s->top_of_stack) //栈空 { printf("Invalid\n"); return; } if(0 == (s->top_of_stack%2)) { index = s->top_of_stack/2; } else { index = (s->top_of_stack+1)/2; } printf("%ld\n",s->array[index]); return; }
