java题解 | #DNA序列#

此题用滑动窗口的思想很好解决。
index是目标下标，maxGC实际上就是滑动窗口里面G，C数量最多的值

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.nextLine();
        int len = sc.nextInt();
        int index = 0;
        int maxGC = 0;
        for(int i = 0;i<s.length()-len;i++){
            int currentGC = 0;
            for(int j = i;j<len+i;j++){
                if(s.charAt(j)=='G'||s.charAt(j)=='C'){
                    currentGC++;
                    if(currentGC>maxGC){
                        index = i;
                        maxGC = currentGC;
                    }
                }
            }
        }
        System.out.println(s.substring(index,index+len));
    }
}