Compare the similarity of two strings

public class Levenshtein {
 
 private int compare(String str, String target) {
  int d[][]; // 矩阵
  int n = str.length();
  int m = target.length();
  int i; // 遍历str的
  int j; // 遍历target的
  char ch1; // str的
  char ch2; // target的
  int temp; // 记录相同字符,在某个矩阵位置值的增量,不是0就是1
  if (n == 0) {
   return m;
  }
  if (m == 0) {
   return n;
  }
  d = new int[n + 1][m + 1];
  for (i = 0; i <= n; i++) { // 初始化第一列
   d[i][0] = i;
  }
 
  for (j = 0; j <= m; j++) { // 初始化第一行
   d[0][j] = j;
  }
 
  for (i = 1; i <= n; i++) { // 遍历str
   ch1 = str.charAt(i - 1);
   // 去匹配target
   for (j = 1; j <= m; j++) {
    ch2 = target.charAt(j - 1);
    if (ch1 == ch2) {
     temp = 0;
    } else {
     temp = 1;
    }
 
    // 左边+1,上边+1, 左上角+temp取最小
    d[i][j] = min(d[i - 1][j] + 1, d[i][j - 1] + 1, d[i - 1][j - 1] + temp);
   }
  }
  return d[n][m];
 }
 
 
 private int min(int one, int two, int three) {
  return (one = one < two ? one : two) < three ? one : three;
 }
 
  
 
 /**
 
 * 获取两字符串的相似度
 
 * 
 
 * @param str
 
 * @param target
 
 * @return
 
 */
 
 public float getSimilarityRatio(String str, String target) {
  return 1 - (float)compare(str, target)/Math.max(str.length(), target.length());
 }
 
  
 
 public static void main(String[] args) {
  Levenshtein lt = new Levenshtein();
  String str = "1#2203NO525FANGXIEROADHUANGPUDISTRICTSHANGHAICHINA";
  String target = "1#2203NO525FANGXIEROADSHANGHAICN";
  System.out.println("similarityRatio="+ lt.getSimilarityRatio(str, target));
 }
}