Scanner scanner = new Scanner(System.in); int n = scanner.nextInt(); int temp=0; // 9 //10-189 //181 if(n<=9){ System.out.println(n); return; } if(n>9&&n<=189){ n=n-9; int shang=n/2; int yushu=n%2; if(yushu==1){ temp= 10+shang; System.out.println( temp/10); return; }else { temp=10+shang-1; System.out.println(temp%10); return; } } if(n>189){ n=n-189; int shang=n/3; int yushu=n%3; if(yushu==0){ temp= 100+shang-1; System.out.println(temp%10); return; }else if(yushu==1){ temp= 100+shang; System.out.println(temp/100); }else { temp= 100+shang; System.out.println(temp/10%10); } }