LeetCode #28 Find the Index of the First Occurrence in a String 在字串中找最早出現的位置/索引

public class Solution {
    public int StrStr(string haystack, string needle) {
        for(int i =0;i<haystack.Length-needle.Length+1;i++)
        {
            if(haystack.Substring(i,needle.Length) == needle)
            {
                return i;
             }
        }
        return -1;
    }
}

public class Solution {
    public int StrStr(string haystack, string needle) {
        return  haystack.IndexOf(needle); 
    }
}

class Solution {
    public int strStr(String haystack, String needle) {
        for(int i =0;i<haystack.length()-needle.length()+1;i++)
        {
            if(haystack.substring(i,i+needle.length()).equals(needle))
            {
                return i;
             }
        }
        return -1;
    }
}

class Solution {
    public int strStr(String haystack, String needle) {
        return  haystack.indexOf(needle);
    }
}

class Solution:
    def strStr(self, haystack: str, needle: str) -> int:
        hl = len(haystack)
        nl = len(needle)
        
        for i in range(0,hl-nl+1):
            if haystack[i:i+nl] == needle:
                return i
        return -1;

class Solution:
    def strStr(self, haystack: str, needle: str) -> int:
        return haystack.find(needle)

/**
 * @param {string} haystack
 * @param {string} needle
 * @return {number}
 */
var strStr = function(haystack, needle) {
        for(let i =0;i<haystack.length-needle.length+1;i++)
        {
            if(haystack.substr(i,needle.length) == needle)
            {
                return i;
             }
        }
        return -1;
};

/**
 * @param {string} haystack
 * @param {string} needle
 * @return {number}
 */
var strStr = function(haystack, needle) {
     return  haystack.indexOf(needle); 
};