問題 https://leetcode-cn.com/problems/implement-strstr/
練習使用JavaScript解答
/**
* @param {string} haystack
* @param {string} needle
* @return {number}
*/
var strStr = function(haystack, needle) {
return haystack.indexOf(needle);
};
題目是讓實現,直接用庫好像不太合適?
再改一下:
/**
* @param {string} haystack
* @param {string} needle
* @return {number}
*/
var strStr = function(haystack, needle) {
var len1 = haystack.length, len2 = needle.length;
var i,j;
for(i=0; (len1-i)>=len2; ++i)
if(haystack.substr(i,len2) == needle)
return i;
return -1;
};