您的问题是在条件中引用字符串中的先前字符。在原始代码中,您具有:
if(i > 1 && j > 1 && s_i == t_j-1 && s_i-1 == t_j){ d[i][j] = Minimum(d[i][j], d[i-2][j-2] + cost);}问题在于值 t_j-1 和 s_i-1 。它们说s和t的第i个字符为减1,其中算法表示您要使用(第i个减1)字符。例如,如果字符串s为“
AFW”,而i为1,则
s_i - 1 = E; //the character value (s[1]='F') minus 1 = 'E's.charAt(i-1) = A; //i-1 = 0, s[0] = 'A'
因此您的条件应为:
if(i > 1 && j > 1 && s_i == t.charAt(j-1) && s.charAt(i-1) == t_j) { d[i][j] = Minimum(d[i][j], d[i-2][j-2] + cost);}编辑:不幸的是,我从阅读代码后无法理解算法,但是这里是Java维基百科页面上Actionscript示例的翻译,它提供了与您的示例匹配的输出:
public static int damerauLevenshteinDistance( String a, String b, int alphabetLength) { final int INFINITY = a.length() + b.length(); int[][] H = new int[a.length()+2][b.length()+2]; H[0][0] = INFINITY; for(int i = 0; i<=a.length(); i++) { H[i+1][1] = i; H[i+1][0] = INFINITY; } for(int j = 0; j<=b.length(); j++) { H[1][j+1] = j; H[0][j+1] = INFINITY; } int[] DA = new int[alphabetLength]; Arrays.fill(DA, 0); for(int i = 1; i<=a.length(); i++) { int DB = 0; for(int j = 1; j<=b.length(); j++) { int i1 = DA[b.charAt(j-1)]; int j1 = DB; int d = ((a.charAt(i-1)==b.charAt(j-1))?0:1); if(d==0) DB = j; H[i+1][j+1] = min(H[i][j]+d, H[i+1][j] + 1, H[i][j+1]+1, H[i1][j1] + (i-i1-1) + 1 + (j-j1-1)); } DA[a.charAt(i-1)] = i; } return H[a.length()+1][b.length()+1]; } private static int min(int ... nums) { int min = Integer.MAX_VALUE; for (int num : nums) { min = Math.min(min, num); } return min; }


