将start<end提到外面来，可以免去比较这一操作

class Solution {
public:
    void reOrderArray(vector<int> &array) {
         int start=0;
         int end=array.size()-1;
         if(array.size()){
            while(array[start]%2)start++;
            while(!(array[end]%2))end--;
         }
         while(start<end){
             swap(array[start],array[end]);
             while(array[start]%2)start++;
             while(!(array[end]%2))end--;
         }
    }
};