public int[] windowSum(int[] nums,int k){
   int[] result = new int[nums.length-k+1];
   if(nums.length==0||nums==null||k<=1)
       return result;
    int count =0;
    for(int i=0,z=0; i<nums.length();i++){
     count++;
     if(count>=k){
        int max=0;
        for(int j=i;j>=i-k+1;j--){
        if(nums[j]>max)
          max=nums[j];
        } 
        result[z++] = max;
     }
   }
   return result;
}