1576. 替换所有的问号

替换指定字符串中的’?’并且使不能有连续一样的字符
遍历的检测到’?’就检测前后位置替换字符

  1.   public static String modifyString(String s) {
  3.         StringBuilder sb = new StringBuilder();
  4.         char[] ss = s.toCharArray();
  5.         if (ss.length==1){
  6.             if(ss[0]=='?'){
  7.                 return "a";
  8.             }
  9.             else return s;
  10.         }
  11.         for (int i = 0; i < ss.length; i++) {
  12.             if (ss[i]=='?'){
  13.                 if (i != 0 && i != ss.length - 1) {
  14.                     char a = (char) (randomNumber(25) + 97);
  15.                     while(a==ss[i-1]||ss[i+1]==a) {
  16.                         a = (char) (randomNumber(25) + 97);
  17.                     }
  18.                     ss[i] = a;
  20.                 }  else if (i==0){
  21.                     char a = (char) (randomNumber(25) + 97);
  22.                     while(ss[i+1]==a) {
  23.                         a = (char) (randomNumber(25) + 97);
  24.                     }
  25.                     ss[i] = a;
  27.                 } else if (i == ss.length - 1) {
  28.                     char a = (char) (randomNumber(25) + 97);
  29.                     while (a == ss[i - 1]) {
  30.                         a = (char) (randomNumber(25) + 97);
  31.                     }
  32.                     ss[i] = a;
  33.                 }
  34.             }
  35.                 sb.append(ss[i]);
  37.         }
  38.         return sb.toString();
  39.     }
  41.     public static int randomNumber(int bound) {
  42.         return (int) (Math.random() * 100000) % bound;
  43.     }