Day 1.25

实现strStr()

题目

代码

class Solution {
    public int strStr(String haystack, String needle) {
        int lenh = haystack.length();
		int lenn = needle.length();
        if(lenn==0)
            return 0;
        if(lenn>lenh)
            return -1;
		char[] s = haystack.toCharArray();
		char[] n = needle.toCharArray();
        //外循环次数为haystack长度减去needle的长度
		for (int i = 0; i < lenh-lenn+1; i++) {
			boolean f = true;
			for (int j = 0,star = i; j < lenn; j++,star++) {
				if(s[star]!=n[j]) {
					f = false;
					break;
				}
			}
			if(f) 
				return i;
		}
		return -1;
    }
}

结果