题解 | #DNA序列#

暴力法遍历

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String s = sc.next();
        int n = sc.nextInt();
        
        
        char[] arr = s.toCharArray();
        int a = 0;
        int index = 0;
        for(int i = 0;i < arr.length - n;i++){
            int ratio = 0;
            for(int j = i;j < i + n;j++){
                 if(arr[j] == 'C' || arr[j] == 'G')
                     ratio++;
            }   
            if(a < ratio){
                a = ratio;
                index = i;
            }
        }
        
        for(int i = index;i < index + n;i++)
            System.out.print(arr[i]);
           
    }
}