Groups of Special-Equivalent Strings
给一个string组, 找其中有几对儿group, 每个group中的string交换奇数or偶数index上的char后相等. 直接counting就可以.
class Solution {
public int numSpecialEquivGroups(String[] A) {
Set<String> seen = new HashSet();
for (String S: A) {
int[] count = new int[52];
for (int i = 0; i < S.length(); ++i)
count[S.charAt(i) - 'a' + 26 * (i % 2)]++;
seen.add(Arrays.toString(count));
}
return seen.size();
}
}