56 lines
1.5 KiB
Java
56 lines
1.5 KiB
Java
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//给定一个字符串，找到它的第一个不重复的字符，并返回它的索引。如果不存在，则返回 -1。
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//
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//
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//
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// 示例：
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//
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// s = "leetcode"
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//返回 0
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//
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//s = "loveleetcode"
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//返回 2
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//
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//
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//
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//
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// 提示：你可以假定该字符串只包含小写字母。
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// Related Topics 队列 哈希表 字符串 计数
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// 👍 414 👎 0
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package leetcode.editor.cn;
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import java.util.HashMap;
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import java.util.Map;
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//387:字符串中的第一个唯一字符
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class FirstUniqueCharacterInAString{
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public static void main(String[] args) {
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//测试代码
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Solution solution = new FirstUniqueCharacterInAString().new Solution();
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}
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//力扣代码
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//leetcode submit region begin(Prohibit modification and deletion)
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class Solution {
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public int firstUniqChar(String s) {
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// for (int i = 0; i < s.length(); i++) {
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// if(!s.substring(i+1).contains(""+s.charAt(i))&&!s.substring(0,i).contains(""+s.charAt(i))){
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// return i;
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// }
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// }
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// return -1;
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Map<Character, Integer> map = new HashMap<>();
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for (int i = 0; i < s.length(); ++i) {
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char ch = s.charAt(i);
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map.put(ch, map.getOrDefault(ch, 0) + 1);
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}
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for (int i = 0; i < s.length(); ++i) {
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if (map.get(s.charAt(i)) == 1) {
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return i;
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}
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}
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return -1;
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}
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}
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//leetcode submit region end(Prohibit modification and deletion)
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}
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