美团网笔试题和面试题答案目
1、一堆硬币，一个机器人，如果是反的就翻正，如果是正的就抛掷一次，无穷多次后，求正反的比例
解答：是不是题目不完整啊，我算的是3：1
2、一个汽车公司的产品，甲厂占40%，乙厂占60%，甲的次品率是1%，乙的次品率是2%，现在抽出一件汽车时次品，问是甲生产的可能性
解答：典型的贝叶斯公式，p(甲|废品) = p(甲 && 废品) / p(废品) = (0.4 × 0.01) /(0.4 × 0.01 + 0.6 × 0.02) = 0.25
3、k链表翻转。给出一个链表和一个数k，比如链表1→2→3→4→5→6，k=2，则翻转后2→1→4→3→6→5，若k=3,翻转后3→2→1→6→5→4，若k=4，翻转后4→3→2→1→5→6，用程序实现
非递归可运行代码：
#include
#include
#include
typedef struct node {
struct node *next;
int data;
} node;
void createList(node *head, int data)
{
node *P, *cur, *new;
P = NULL;
cur = *head;
while (cur != NULL) {
P = cur;
cur = cur->next;
}
new = (node *)malloc(sizeof(node));
new->data = data;
new->next = cur;
if (P == NULL)
*head = new;
else
P->next = new;
}
void printLink(node *head)
{
while (head->next != NULL) {
printf("%d ", head->data);
head = head->next;
}
printf("%d ", head->data);
}
int linkLen(node *head)
{
int len = 0;
while (head != NULL) {
len ++;
head = head->next;
}
return len;
}
node* reverseK(node *head, int k)
{
int i, len, time, now;
len = linkLen(head);
if (len < k) {
return head;
} else {
time = len / k;
}
node *newhead, *Pv, *next, *old, *tail;
for (now = 0, tail = NULL; now < time; now ++) {
old = head;
for (i = 0, Pv = NULL; i < k; i ++) {
next = head->next;
head->next = Pv;
Pv = head;
head = next;
}
if (now == 0) {
newhead = Pv;
}
old->next = head;
if (tail != NULL) {
tail->next = Pv;
}
tail = old;
}
if (head != NULL) {
tail->next = head;
}
return newhead;
}
int main(void)
{
int i, n, k, data;
node *head, *newhead;
while (scanf("%d %d", &n, &k) != EOF) {
for (i = 0, head = NULL; i < n; i ++) {
scanf("%d", &data);
createList(&head, data);
}
printLink(head);
newhead = reverseK(head, k);
printLink(newhead);
}
return 0;
}
