165. Compare Version Numbers

今天项目里遇到以"." 、""、“|”分割字符串，直接用"." 、""、“|”无法分割，因为"." 、""、“|”是特殊字符，需要转义，"." 、""、“|”。

class Solution {
      public int compareVersion(String version1, String version2) {
          String[] arr1 = version1.split("\\.");
          String[] arr2 = version2.split("\\.");
          int n = arr1.length>arr2.length?arr1.length:arr2.length;
          int temp1[] = new int [n];
          int temp2[] = new int [n];
          for(int i = 0 ; i < arr1.length ; i++) {
              temp1[i] = Integer.parseInt(arr1[i]);
          }
          for(int i = 0 ; i < arr2.length ; i++) {
              temp2[i] = Integer.parseInt(arr2[i]);
          }
          int flag = 0;
          while(flag<n) {
              if(temp1[flag]<temp2[flag])
                  return -1;
              else if(temp1[flag]>temp2[flag])
                  return 1;
              flag++;
          }
          return 0;
        }
      }

精简~

class Solution {
   public int compareVersion(String s1, String s2) {
          int i = 0 ; 
          int j = 0 ; 
          while( i < s1.length() || j < s2.length()) {
              int x = i ;
              int y = j ;
              while(x<s1.length()&&s1.charAt(x)!='.')x++;
              while(y<s2.length()&&s2.charAt(y)!='.')y++;
              int a = i==x?0:Integer.valueOf(s1.substring(i, x));
              int b = j==y?0:Integer.valueOf(s2.substring(j, y));
              if(a>b)return 1;
              else if(a<b)return -1;
              i = x+1;
              j = y+1;
          }
          return 0;
        }
      }