题解 | #DNA序列#
DNA序列
http://www.nowcoder.com/practice/e8480ed7501640709354db1cc4ffd42a
思路：分割成子串，对子串进行CG计数，记录最大数的下标。要是能碰到这么简单的题目就好了。。动态规划应该也可以做出来，不过不会做。
import java.util.Scanner;
public class DNASequence {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
while (sc.hasNextLine()) {
String s = sc.nextLine();
int split = Integer.parseInt(sc.nextLine());
int maxIndex = 0;
int maxCnt = 0;
for (int i = 0; i < s.length() - split; i++) {
int cnt = countCAndG(s.substring(i, i + split));
if (cnt > maxCnt) {
maxCnt = cnt;
maxIndex = i;
}
}
System.out.println(s.substring(maxIndex, maxIndex + split));
}
}
private static int countCAndG(String sub) {
char[] chs = sub.toCharArray();
int count = 0;
for (int i = 0; i < chs.length; i++) {
if (chs[i] == 'C' || chs[i] == 'G') {
count++;
}
}
return count;
}
}
