1.描述
Given two strings s and t, determine if they are isomorphic.
Two strings are isomorphic if the characters in s can be replaced to get t.
All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character but a character may map to itself.
For example,
Given "egg", "add", return true.
Given "foo", "bar", return false.
Given "paper", "title", return true.
Note:
You may assume both s and t have the same length.
2.分析
3.代碼
bool isIsomorphic(char* s, char* t) {
if (strlen(s) != strlen(t)) return false;
if (0 == strlen(s) || 0 == strlen(t)) return true;
char mapS2T[256];
char mapT2S[256];
memset(mapS2T, 0, 256 * sizeof(char));
memset(mapT2S, 0, 256 * sizeof(char));
unsigned int len = strlen(s);
for (unsigned int i = 0; i < len; ++i) {
if (0 == mapS2T[s[i]] && 0 == mapT2S[t[i]]) {
mapS2T[s[i]] = t[i];
mapT2S[t[i]] = s[i];
} else if (mapS2T[s[i]] != t[i] || mapT2S[t[i]] != s[i])
return false;
}
return true;
}
