leetcode 242. Valid Anagram

leetcode 242. Valid Anagram

题目

Given two strings s and t, write a function to determine if t is an anagram of s.

For example,
s = “anagram”, t = “nagaram”, return true.
s = “rat”, t = “car”, return false.

Note:
You may assume the string contains only lowercase alphabets.

解

public class Solution {
    public boolean isAnagram(String s, String t) {
        char[] ss=s.toCharArray();
        char[] tt=t.toCharArray();

        int[] count_s=new int[26];
        int[] count_t=new int[26];

        for(int i=0;i<ss.length;i++){
            //count_s[i]=0;//java自动初始化为0；
            count_s[ss[i]-97]++;
        }

        for(int j=0;j<tt.length;j++){
            count_t[tt[j]-97]++;
        }

        for(int k=0;k<26;k++){
            if(count_s[k]!=count_t[k]){
                return false;
            }
        }
        return true;

    }
}

小结

1，string转成char[]，函数是toCharArray();
2，数组的长度是length；
3，a的ASCII码是97。