20180207duplicate

class Solution {
public:
    // Parameters:
    //        numbers:     an array of integers
    //        length:      the length of array numbers
    //        duplication: (Output) the duplicated number in the array number
    // Return value:       true if the input is valid, and there are some duplications in the array number
    //                     otherwise false
    bool duplicate(int numbers[], int length, int* duplication) {
        bool result=false;
        if(length>=1){
            int hash[length];
        for(int i=0;i<length;i++)
            hash[i]=0;
        for(int i=0;i<length;i++){
            hash[numbers[i]]++;
            if(hash[numbers[i]]>1){
                *duplication=numbers[i];
                result=true;
                break;
            }
        }
        }
        return result;
    }
};