leetcode 28. 實現strStr()

標籤：har   圖片   style   class   opened   bool   while   splay   none   

class Solution {    public int strStr(String haystack, String needle) {        int i = 0, j = 0;        int a = haystack.length();        int b = needle.length();        if(a<b) return -1;        else if(b==0 || haystack.equals(needle)) return 0;        else {            while(i < a && j < b) {                if(needle.charAt(j) != haystack.charAt(i)) {                    i=i-j+1;                    j=0;                }                else {                    i++;                    j++;                }            }            if(j==b) return i-j;            else return -1;        }    }}

雙指標

 

 

class Solution {    public int strStr(String haystack, String needle) {                if(haystack.length() == 0&&needle.length() != 0) return -1;                int l1=haystack.length();                int l2=needle.length();                boolean flag;                for(int i = 0 ; i <= l1-l2; i++){                    flag = true;                    for(int j = 0 ; j < needle.length() ; j ++) {                        if(haystack.charAt(i+j) != needle.charAt(j)) {                            flag = false;                            break;                        }                    }                    if(flag) return i;                }                return -1;            }    }

簡潔

 

leetcode 28. 實現strStr()