leetcode 49. Group Anagrams

需要用到素数表，我们需要将字母转换成素数

var prime = [2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,
 53,59,61,67,71,73,79,83, 89,97,101];
    
var groupAnagrams = function(strs) {
  
    var hash = {}, ret = [], index = 0;
    for(let word of strs){
        var sum  = 1;
        for(let c of word){
           var i = c.charCodeAt(0) - 97;
           sum *= prime[ i ]
        }
        if( sum in hash){
            ret [ hash[sum] ].push(word)
        }else{
            hash[sum] = index++
            ret[ hash[sum] ] = [word] 
        } 
    }
        
    return ret;
    
};