题目

leetcode-cn.com/problems/im…

思路

• indexOf
• 循环遍历（即便是indexOf一秒解决但还是要正常考虑的是屑x

题解

var strStr = function(haystack, needle) { return haystack.indexOf(needle) };

var strStr = function(haystack, needle) {
    if (needle == '') return 0
    if (needle.length > haystack.length) return -1
    var i, j;
    for (i = 0; i < haystack.length; i++) {
        if (needle.charAt(0) == haystack.charAt(i)) {
            for (j = 1; j < needle.length; j++)
                if (needle.charAt(j) != haystack.charAt(i + j)) break
            if (j == needle.length) return i
        }
    }
    return -1
};