这个题目不看例子，根本就不知道是个什么鬼啊。需要注意同一组数据中每次的字符替换都建立在上一次的基础上。 import java.util.*; public class Main { public static void main(String[] args) { Scanner in = new Scanner(System.in); while (in.hasNext()) { int n = in.nextInt(); int m = in.nextInt(); StringBuilder sb = new StringBuilder(in.next()); for (int i = 0; i < m; i++) { int count = 0; int x = in.nextInt(); char c = in.next().charAt(0); sb.setCharAt(x-1, c); StringBuilder cp = new StringBuilder(sb.toString()); int length = cp.length(); int j = 0; while (j < length - 1) { if (cp.charAt(j) == '.' && cp.charAt(j+1) == '.') { cp.replace(j, j+2, "."); count++; length = cp.length(); } else { j++; } } System.out.println(count); } } } }