题解 | #MP3光标位置#

#include <stdio.h>

int main() {
    int muinum = 0;
    char c;
    int now = 1;
    int pagetop = 1;
    int pagebot = 4;
    scanf("%d",&muinum);
    while (~scanf("%c",&c)) {
    if(muinum>4){
        if(c == 'U'){
            if(now == pagetop && pagetop!=1)
            {
                now--;
                pagebot--;
                pagetop--;
            }
            else if(now == pagetop && pagetop ==1)
            {
                now = muinum;
                pagebot = muinum;
                pagetop = muinum -3;
            }
            else if (now!=pagetop) {
                now--;
            }
        }

        else if(c == 'D'){
            if(now == pagebot && pagebot!=muinum)
            {
                now++;
                pagebot++;
                pagetop++;
            }
            else if(now == pagebot && pagebot ==muinum)
            {
                now = 1;
                pagebot = 4;
                pagetop = 1;
            }else if(now!=pagebot)
            {
                now++;
            }
        }
    
    }
    else if(muinum<=4)
    {
        pagebot = muinum;
        if(c == 'U')
        {
            now--;
        }
        else if(c=='D')
        {
            now++;
        }

       if(now == 0) now = muinum;
       else if(now == muinum+1) now = 1;
    }
    }
    for(int i=pagetop;i<=pagebot;i++)
    {
        printf("%d ",i);
    }
    
    printf("\n%d",now);
}