【九度】题目1415：不一样的循环队列
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题目地址：http://ac.jobdu.com/problem.php?pid=1415
题目描述： -
大家都知道数据结构里面有一个结构叫做循环队列。顾名思义，这是一个队列，并且是循环的。但是现在，淘气的囧哥给这个循环队列加上了一些规矩，其中有5条指令:
(1) Push K, 让元素K进队列。
(2) Pop，对头元素出队列。
(3) Query K，查找队列中第K个元素，注意K的合法性。
(4) Isempty，判断队列是否为空。
(5) Isfull，判断队列是否已满。
现在有N行指令，并且告诉你队列大小是M。
- 输入：
-
第一行包含两个整数N和M。1<=N,M<=100000。
接下来有N行，表示指令，指令格式见题目描述。
其中元素均在int范围。
- 输出：
-
对于指令（1），若队列已满，输出failed，否则不做输出。
对于指令（2），若队列已空，输出failed，否则不做输出。
对于指令（3），输出队列中第K个元素，若不存在，输出failed。
对于指令（4）和（5），则用yes或者no回答。
详情见样例。
- 样例输入：
-
12 2
-
Push 1
-
Push 2
-
Push 3
-
Query 2
-
Query 3
-
Isempty
-
Isfull
-
Pop
-
Pop
-
Pop
-
Isempty
-
Isfull
- 样例输出：
-
failed
-
2
-
failed
-
no
-
yes
-
failed
-
yes
-
no
循环队列，底层实现是数组，给出Java和C++的实现。
其实可以不用结构体，直接数组就可以。
C++ AC
#include <stdio.h>
#include <string>
#include <string.h>
using namespace std;
#define INF 10000000;
const int maxm = 100002;
struct QueueLoop{
int array[maxm];
int front;
int rear;
};
QueueLoop queue;
int n,m,i;
int len;
bool IsEmpty(){
int front = queue.front;
int rear = queue.rear;
if (rear == front) {
return true;
}
return false;
}
bool Isfull(){
int front = queue.front;
int rear = queue.rear;
if ((rear + 1) % len == front) {
return true;
}
return false;
}
bool pushElement(int k){
if (Isfull()) {
return false;
}
int rear = queue.rear;
queue.array[rear] = k;
queue.rear = (rear+1) % len;
return true;
}
bool popElement(){
if (IsEmpty()) {
return false;
}
int front = queue.front;
queue.front = (front+1) % len;
return true;
}
void queryElement(int k){
int front = queue.front;
int rear = queue.rear;
if ( k <= 0 || rear - front < k) {
printf("failed\n");
}else{
printf("%d\n",queue.array[k + front - 1]);
}
}
int main(){
while(scanf("%d%d",&n,&m) != EOF){
queue.front = 0;
queue.rear = 0;
len = m+1;
char operate[15];
for(i = 0 ; i < n; i++){
scanf("%s",operate);
if (strcmp(operate,"Push") == 0) {
int k;
scanf("%d",&k);
if (!pushElement(k)) {
printf("failed\n");
}
}else if (strcmp(operate,"Pop") == 0) {
if (!popElement()) {
printf("failed\n");
}
}else if (strcmp(operate,"Query") == 0) {
int k;
scanf("%d",&k);
queryElement(k);
}else if (strcmp(operate,"Isempty") == 0) {
printf("%s\n",IsEmpty() == true ? "yes" :"no");
}else {
printf("%s\n",Isfull() == true ? "yes" :"no");
}
}
}
return 0;
}
/**************************************************************
Problem: 1415
User: wangzhenqing
Language: C++
Result: Accepted
Time:130 ms
Memory:1412 kb
****************************************************************/
Java AC 做法1
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;
public class Main {
/*
* 1415
*/
private static QueueLoop queue;
private static int len;
public static void main(String[] args) throws Exception{
StreamTokenizer st = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
while (st.nextToken() != StreamTokenizer.TT_EOF) {
int n = (int) st.nval;
st.nextToken();
int m = (int) st.nval;
queue = new QueueLoop(m);
len = m + 1;
while (n > 0) {
n--;
st.nextToken();
String operate = st.sval;
if (operate.equals("Push")) {
st.nextToken();
int k = (int) st.nval;
if (!pushElement(k)) {
System.out.println("failed");
}
}else if (operate.equals("Pop")) {
if (!popElement()) {
System.out.println("failed");
}
}else if (operate.equals("Query")) {
st.nextToken();
int k = (int) st.nval;
Integer value = queryElement(k);
if (value == null) {
System.out.println("failed");
}else {
System.out.println(value);
}
}else if (operate.equals("Isempty")) {
System.out.println(IsEmpty() == true ? "yes" :"no");
}else {
System.out.println(Isfull() == true ? "yes" :"no");
}
}
}
}
private static boolean pushElement(int k){
if (Isfull()) {
return false;
}
int rear = queue.rear;
int array[] = queue.array;
array[rear] = k;
queue.array = array;
queue.rear = (rear+1) % len;
return true;
}
private static boolean popElement(){
if (IsEmpty()) {
return false;
}
int front = queue.front;
queue.front = (front+1) % len;
return true;
}
private static Integer queryElement(int k){
int front = queue.front;
int rear = queue.rear;
int array[] = queue.array;
if ( k <= 0 || rear - front < k) {
return null;
}
return array[k + front - 1];
}
private static boolean IsEmpty(){
int front = queue.front;
int rear = queue.rear;
if (rear == front) {
return true;
}
return false;
}
private static boolean Isfull(){
int front = queue.front;
int rear = queue.rear;
if ((rear + 1) % len == front) {
return true;
}
return false;
}
public static class QueueLoop{
int array[];
int front;
int rear;
public QueueLoop(int[] array, int front, int rear) {
super();
this.array = array;
this.front = front;
this.rear = rear;
}
public QueueLoop(int size) {
array = new int[size+1];
front = 0;
rear = 0;
}
public QueueLoop() {
super();
}
}
}
/**************************************************************
Problem: 1415
User: wzqwsrf
Language: Java
Result: Accepted
Time:2280 ms
Memory:43496 kb
****************************************************************/
Java AC 做法2
import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.io.StreamTokenizer;
public class Main {
/*
* 1415
*/
private static int array[];
private static int front , rear;
public static void main(String[] args) throws Exception{
StreamTokenizer st = new StreamTokenizer(new BufferedReader(new InputStreamReader(System.in)));
while (st.nextToken() != StreamTokenizer.TT_EOF) {
int n = (int) st.nval;
st.nextToken();
int m = (int) st.nval;
array = new int[m+1];
front = rear = -1;
while (n > 0) {
n--;
st.nextToken();
String operate = st.sval;
if (operate.equals("Push")) {
st.nextToken();
int k = (int) st.nval;
if (rear - front == m) {
System.out.println("failed");
}else {
rear ++;
array[rear] = k;
}
}else if (operate.equals("Pop")) {
if (front == rear) {
System.out.println("failed");
}else {
front++;
}
}else if (operate.equals("Query")) {
st.nextToken();
int k = (int) st.nval;
if ( k <= 0 || rear - front < k) {
System.out.println("failed");
}else {
System.out.println(array[front + k]);
}
}else if (operate.equals("Isempty")) {
System.out.println(rear == front ? "yes" :"no");
}else {
System.out.println(rear - front == m ? "yes" :"no");
}
}
}
}
}
/**************************************************************
Problem: 1415
User: wzqwsrf
Language: Java
Result: Accepted
Time:2190 ms
Memory:42104 kb
****************************************************************/