strSimilarity2Number: function (s, t) {
     var n = s.length, m = t.length, d = [];
     var i, j, s_i, t_j, cost;
     if (n == 0) return m;
     if (m == 0) return n;
     for (i = 0; i <= n; i++) {
         d[i] = [];
         d[i][0] = i;
     }
     for (j = 0; j <= m; j++) {
         d[0][j] = j;
     }
     for (i = 1; i <= n; i++) {
         s_i = s.charAt(i - 1);
         for (j = 1; j <= m; j++) {
             t_j = t.charAt(j - 1);
             if (s_i == t_j) {
                 cost = 0;
             } else {
                 cost = 1;
             }
             d[i][j] = self.Minimum(d[i - 1][j] + 1, d[i][j - 1] + 1, d[i - 1][j - 1] + cost);
         }
     }
     return d[n][m];
 },
//两个字符串的相似程度，并返回相似度百分比
 strSimilarity2Percent: function (s, t) {
     var l = s.length > t.length ? s.length : t.length;
     var d = self.strSimilarity2Number(s, t);
     return (1 - d / l).toFixed(4);
 },
 Minimum: function (a, b, c) {
     return a < b ? (a < c ? a : c) : (b < c ? b : c);
 },