LintCode 哈希函数题目代码

class Solution {
    /**
     * @param key: A String you should hash
     * @param HASH_SIZE: An integer
     * @return an integer
     */
    public int hashCode(char[] key,int HASH_SIZE) {
        // write your code here
         int len = key.length;
        long hashcode = 0;
        long base = 1;
        for(int i=len-1;i>=0;i--){
            hashcode = hashcode  + Integer.valueOf(key[i])*base % HASH_SIZE;
            base = base *33% HASH_SIZE;
        }
        return (int)hashcode%HASH_SIZE;
    }
};

class Solution {
    /**
     * @param key: A String you should hash
     * @param HASH_SIZE: An integer
     * @return an integer
     */
    public int hashCode(char[] key,int HASH_SIZE) {
        // write your code here
        long ans = 0;
        for(int i = 0; i < key.length;i++) {
            ans = (ans * 33 + (int)(key[i])) % HASH_SIZE; 
        }
    return (int)ans;
    }
};