【LeetCode】387 First Unique Character in a String(java实现)
2016-10-20 00:37
531 查看
原题
Given a string, find the first non-repeating character in it and return it’s index. If it doesn’t exist, return -1.Examples: s = "leetcode" return 0. s = "loveleetcode", return 2.
Note: You may assume the string contain only lowercase letters.
题目要求
题目的意思是找出字符串中第一个不重复的字母,字符串中,如果存在该这样的字符,则返回字符在字符串中的索引值,如果不存在,则返回-1。注意:假设字符串中只有小写字母,这稍微简化了一下题目。难度:Eazy
解法
解法:现在只要一看到字母,首先想到的解法就是一个26个元素的数组,索引表示字母,索引对应的值即出现的字数。对字符串进行两次遍历,第一次算出每个字符出现的次数,第二次遍历找出第一个字符即可。public int firstUniqChar(String s) { int pos = -1; int []bits = new int[26]; for (int i = 0; i < s.length(); i++) { char c = s.charAt(i); ++bits[c - 'a']; } for (int i = 0; i < s.length(); i++) { char c = s.charAt(i); if (bits[c - 'a'] == 1) { pos = i; break; } } return pos; }
相关文章推荐
- 【LeetCode】387 First Unique Character in a String(java实现)
- Java [Leetcode 387]First Unique Character in a String
- LeetCode - 387 - First Unique Character in a String
- leetcode 387 First Unique Character in a String C++
- Leetcode 387 First Unique Character in a String
- 【python】【leetcode】【算法题目387—First Unique Character in a String】
- Leetcode-387 First Unique Character in a String
- leetcode-387-First Unique Character in a String
- 算法系列(16)Leetcode 387 First Unique Character in a String
- LeetCode 387 First Unique Character in a String
- 【LeetCode-387】First Unique Character in a String(C++)
- [LeetCode] First Unique Character in a String(Java)
- LeetCode 387 First Unique Character in a String
- leetcode_387 First Unique Character in a String
- leetcode387:First Unique Character in a String
- LeetCode(387)First Unique Character in a String
- LeetCode387 First Unique Character in a String
- leetcode 387 First Unique Character in a String
- LeetCode 387:First Unique Character in a String
- LeetCode 387 First Unique Character in a String