The base case is whenever S1 or S2 is a zero-length string.

（基线条件（basecase）是S1或S2为长度为零的字符串的情形。

youdao

In this case, the LCS of S1 and S2 is clearly a zero-length string.

在这种情况下，S1和S2的LCS显然是长度为零的字符串。

youdao

In this case, the LCS of S1 and S2 is clearly a zero-length string.

在这种情况下，S1和S2的LCS显然是长度为零的字符串。

youdao