快速排序及其应用

int partion(int *x,int low,int high){

   int temp=x[low];
   int i=low;
   int j=high+1;

   while(true){
     while(x[++i]<temp);
     while(x[--j]>temp);
     if(i>=j) break;
     swap(x[i],x[j]);
   }
   x[low]=x[j];
   x[j]=temp;
   return j;
}
int quickpass(int *x,int low,int high){
    if(low<high){
        int p=partion(x,low,high);
        quickpass(x,low,p-1);
        quickpass(x,p+1,high);
    }
}

//求第k小的元素
int mink(int *m,int low,int high,int k){

    if(low==high) return m[low];
    int f=partion(m,low,high);
    //左边的元素的个数
    int lnum=f-low+1;
    if(lnum>=k)
       return mink(m,low,f,k);
    else
       return mink(m,f+1,high,k-lnum);
}