1442 Black Box

最先，是自己用插入排序的方法做的，时间超出，没有通过。

代码如下：

import java.util.Scanner;

import java.util.Arrays;

public class BlackBox{

staticint M,N;//这些变量必须是类变量

static int[]A,u;

public BlackBox(){//constructor

}

privatevoid Input(){//get the inputs of M, N, A, and u

Scanner input=new Scanner(System.in);

M=input.nextInt();

N=input.nextInt();

A=newint[M+1];

u=newint[N+1];

int i;

for (i=1;i<=M;i++){

A[i]=input.nextInt();

}

for (i=1;i<=N;i++){

u[i]=input.nextInt();

}

input.close();

}

private void Do(){

int i=0;

for (int k=1;k<=M;k++){

InsertSort(A,1,k);

while(i<N&&u[i+1]==k){

i++;

System.out.println(A[i]);

}

}

}

private void InsertSort(int[] A,int a, int b){

int i=a;

while (i<b&&A[i]<=A[b]) i++;

if (i<b){

int temp=A[b];

for (int j=b-1; j>=i; j--){

A[j+1]=A[j];

}

A[i]=temp;

}

}

public staticvoid main(String[] args){

BlackBox hi=new BlackBox();

hi.Input();

hi.Do();

}

}

后来，模仿大牛的代码，用一个大顶堆和一个小顶堆解决了问题。通过了。

代码如下：

import java.util.Arrays;

import java.util.Scanner;

public class BlackBox2{

staticint M,N;//这些变量必须是类变量

static int[]A,u;

public BlackBox2(){//constructor

}

privatevoid Input(){//get the inputs of M, N, A, and u

Scanner input=new Scanner(System.in);

M=input.nextInt();

N=input.nextInt();

A=newint[M+1];

u=newint[N+1];

int i;

for (i=1;i<=M;i++){

A[i]=input.nextInt();

}

for (i=1;i<=N;i++){

u[i]=input.nextInt();

}

input.close();

}

private void build1(int[] tree1,int k){//从下至上，变为大顶堆

int p=k;

while (p>1&&tree1[p]>tree1[p/2]){

int temp=tree1[p];

tree1[p]=tree1[p/2];

tree1[p/2]=temp;

p=p/2;

}

}

private void build2(int[] tree2,int k){//从下至上，变为小顶堆

int p=k;

while (p>1&&tree2[p]<tree2[p/2]){

int temp=tree2[p];

tree2[p]=tree2[p/2];

tree2[p/2]=temp;

p=p/2;

}

}

private void adapt1(int[] tree1,int k){

//从上至下，变为大顶堆

int p=1;

int son;

while(2*p<=k){

if (k==2*p||tree1[p*2]>=tree1[p*2+1])

son=p*2;

else

son=p*2+1;

if (tree1[p]<tree1[son]){

int temp=tree1[p];

tree1[p]=tree1[son];

tree1[son]=temp;

p=son;

}else

p=k;

}

}

private void adapt2(int[] tree2,int k){

//从上至下，变为小顶堆

int p=1;

int son;

while(2*p<=k){

if(k==2*p||tree2[p*2]<=tree2[p*2+1])

son=p*2;

else

son=p*2+1;

if (tree2[p]>tree2[son]){

int temp=tree2[p];

tree2[p]=tree2[son];

tree2[son]=temp;

p=son;

}else

p=k;

}

}

private void Do(){

int k=0;

int k1=0,k2=0;

int[] tree1=newint [M+1];

int[] tree2=newint [M+1];

for (int i=1; i<=N; i++){

int a=u[i];

for (int j=k+1;j<=a;j++){

tree2[++k2]=A[j];

build2(tree2,k2);

}

k=a;

tree1[++k1]=tree2[1];

build1(tree1,k1);

tree2[1]=tree2[k2--];

adapt2(tree2,k2);

while(k1!=0&&k2!=0&&tree1[1]>tree2[1]){

int temp=tree2[1];

tree2[1]=tree1[1];

tree1[1]=temp;

adapt1(tree1,k1);

adapt2(tree2,k2);

}

System.out.println(tree1[1]);

}

}

public staticvoid main(String[] args){

BlackBox2 hi=new BlackBox2();

hi.Input();

hi.Do();

}

}