| public static LCSDistance ( String word, Array keys ) : Int32 | ||
| word | String | |
| keys | Array | 多个关键字。长度必须大于0，必须按照字符串长度升序排列。 |
| return | Int32 | |
public static Int32 LCSDistance(String word, String[] keys)
{
var sLength = word.Length;
var result = sLength;
var flags = new Boolean[sLength];
var C = new Int32[sLength + 1, keys[keys.Length - 1].Length + 1];
//int[,] C = new int[sLength + 1, words.Select(s => s.Length).Max() + 1];
foreach (var key in keys)
{
var wLength = key.Length;
Int32 first = 0, last = 0;
Int32 i = 0, j = 0, LCS_L;
//foreach 速度会有所提升，还可以加剪枝
for (i = 0; i < sLength; i++)
for (j = 0; j < wLength; j++)
if (word[i] == key[j])
{
C[i + 1, j + 1] = C[i, j] + 1;
if (first < C[i, j])
{
last = i;
first = C[i, j];
}
}
else
C[i + 1, j + 1] = Math.Max(C[i, j + 1], C[i + 1, j]);
LCS_L = C[i, j];
if (LCS_L <= wLength >> 1)
return -1;
while (i > 0 && j > 0)
{
if (C[i - 1, j - 1] + 1 == C[i, j])
{
i--;
j--;
if (!flags[i])
{
flags[i] = true;
result--;
}
first = i;
}
else if (C[i - 1, j] == C[i, j])
i--;
else// if (C[i, j - 1] == C[i, j])
j--;
}
if (LCS_L <= (last - first + 1) >> 1)
return -1;
}
return result;
}
