题解 | #MP3光标位置#
MP3光标位置
https://www.nowcoder.com/practice/eaf5b886bd6645dd9cfb5406f3753e15
#include <cstring>
#include <iostream>
using namespace std;
int main()
{
int curList[4]={1,2,3,4}; //保存当前歌曲列表
int num;
cin>>num;
int*arr=new int[num];
for(int i=0;i<num;++i)
arr[i]=i+1; //初始化歌曲列表
int cursor=0; //光标位置
char*order=new char[100];
memset(order, 0, 100);
cin>>order;
while(*order)
{
char c=*order;
if(c=='U')
{
if(num>=4)
{
if(arr[cursor]==curList[0]) //光标位于歌曲列表头
{
if(cursor==0)
{
cursor=num-1;
curList[0]=arr[num-4];
curList[1]=arr[num-3];
curList[2]=arr[num-2];
curList[3]=arr[num-1];
}
else
{
curList[0]=arr[cursor-1];
curList[1]=arr[cursor];
curList[2]=arr[cursor+1];
curList[3]=arr[cursor+2];
--cursor;
}
}
else
--cursor;
}
else
{
if(cursor==0)
cursor=num-1;
else
--cursor;
}
}
else if(c=='D')
{
if(num>=4)
{
if(arr[cursor]==curList[3]) //光标位于歌曲列表尾
{
if(cursor==num-1)
{
cursor=0;
curList[0]=arr[0];
curList[1]=arr[1];
curList[2]=arr[2];
curList[3]=arr[3];
}
else
{
curList[0]=arr[cursor-2];
curList[1]=arr[cursor-1];
curList[2]=arr[cursor];
curList[3]=arr[cursor+1];
++cursor;
}
}
else
++cursor;
}
else
{
if(cursor==num-1)
cursor=0;
else
++cursor;
}
}
++order;
}
if(num<=4)
{
for(int i=0;i<num;++i)
cout<<arr[i]<<" ";
}
else
{
for(int i=0;i<4;++i)
cout<<curList[i]<<" ";
}
cout<<"\n";
cout<<cursor+1;
}
// 64 位输出请用 printf("%lld")
