数组中的逆序对

public class Solution {
    public int count=0;
    //方法一、暴力**
    public int InversePairs(int [] array) {
        if(array==null||array.length==0){
            return 0;
        }
        int p=0;
        for(int i=0;i!=array.length;i++){

            for( int j=i+1;j!=array.length;j++)
            {
                if(array[i]>array[j]){
                ++p;
                p=p%1000000007;
                }
            }   
        }

        return p%1000000007;
    }

    //方法二:归并排序的思想
    public int InversePairs2(int [] array) {
        if(array==null||array.length==0){
            return 0;
        }   
        Mainmerge(array,0,array.length-1);
        return count%1000000007;
    }
    //递归调用归并函数的主体
    public void Mainmerge(int[]arr,int start,int end){
         if(start>=end){
              return;
         }
         int mid=start+(end-start)/2;
         Mainmerge(arr,start,mid);
         Mainmerge(arr,mid+1,end);
         merge(arr,start,mid,end);
    }
    //合并函数
    public void merge(int[]array,int start,int mid,int end){
        int[]tmp=new int[end-start+1];
        int i=start,j=mid+1,k=0;
        while(i<=mid&&j<=end){

             if(array[i]<=array[j])
             {
                 tmp[k++]=array[i++];
             }else{
                 tmp[k++]=array[j++];
                 count+=mid-i+1;
                 if(count>1000000007){
                    count=count%1000000007;
                 }
             }
        }
        while(i<=mid)
        {
                tmp[k++]=array[i++];
        }
        while(j<=end){
                tmp[k++]=array[j++];
        }

        //将已排好序的数组拷贝到原数组
        for(k=0;k!=tmp.length;k++){
            array[start+k]=tmp[k];
        }
    }
    public static void main(String[]args){
        //System.out.println("Hello");
        // int i=1000000007;
        // System.out.println(i);
        // System.out.println(Integer.MAX_VALUE);
        int[]arr={1,2,3,4,5,6,7,0};
        Solution s=new Solution();
        System.out.println(s.InversePairs2(arr));
        for(int i=0;i!=arr.length;i++)
        {
             System.out.print(arr[i]+" ");
        }

    }

}