Technique: Binary search animation (recursive)

    Step by step animation. For the programming beginners to get a better understanding of binary search.(Click snail button to start animation and click it again to go back to the first page)
    Search a keyword, if found, return the index of the item in the array, if not found, return the index where the element should be inserted.(4 example keywords)





Cost: O(logn)

Binary search code in C++:

int binsearch( vector<string> words, int low, int high, string word )

{

     if ( high < low ) return -low ;//position to insert

     int mid = (low+high) / 2;

     if(words[mid]==word)

     {

         return mid;

     }

     else if ( word < words[mid] )

     {

         return binsearch( words, low, mid-1, word );

     }

     else

     {

         return binsearch( words, mid+1, high, word );

     }

}


More technique animations:

Quick Sort
Heap Sort
Merge Sort 
Bubble Sort 
Selection Sort 

Technique: Quick sort animation

    First round quick sort step by step animation, for the programming beginners to get a better understanding of quick sort algorithm.(Click snail button to start animation and click it again to go back to the first page)



Cost: O(nlogn)
Worst case: O(n^2)
Best case: O(nlogn)

Quick sort code in C++:

void quickSort(int arr[], int left, int right) {

      int i = left, j = right;

      int temp;

      int pivot = arr[(left + right) / 2];

      /* partition */

      while (i <= j) {

            while (arr[i] < pivot)

                  i++;

            while (arr[j] > pivot)

                  j--;

            if (i <= j) {

                  temp = arr[i];

                  arr[i] = arr[j];

                  arr[j] = temp;

                  i++;

                  j--;

            }

      };

      /* recursion */

      if (left < j)

            quickSort(arr, left, j);

      if (i < right)

            quickSort(arr, i, right);

}



More technique animations:

Heap Sort
Binary Search
Merge Sort 
Bubble Sort 
Selection Sort 

Jiangnan 江南

    I thought I loved traveling before I arrived here. Later, I suddently found a place, without history, without culture, only beautiful views is meaningless for me. I started to read Chinese history again. A history book writer said history is not a story,but is real,which gives me a new angle to view it. People in history spent every single seconds in their lives just as what you are doing now.Thousands of years, technology was improved, environment was changed, but people are still there. They repeatedly did the same thing and considered about the same questions.
 
    For long time, a huge question always confused me: what my life will be?  I tried to find the answer by searching the people with similar personality, background and experiences in history. I know it is silly because I will finally figure it out at the end of my life. I believe that people can control their destiny somehow. But I also believe everyone follows a certain path, not designed by any supernatural being, but by the historical rules. We can find it if we do a huge data analysis of all the people in history，but it is a secret of life.

    Back to today's topic. Jiangnan is the general name of several provinces located in the middle south of China, near the east coast.Many cities have more than 5000 years of history and 2000 years of culture. It is not my hometown, but I was deeply impressed. In history, the richest people, literati and poets all lived there. Not like the north, where the wars, disasters and famine often happened; Not like the further south, where the land was uncivilized; Jiangnan is a place represented peace, harmony and richness.



    This Flash is not a picture gallery, if you want, you can find many photos online.(http://allold.blogspot.com/2012/02/old-garden-chinese-garden-art.html) I just want to show what Jiangnan looks like and why it is special. My favorite picture is the right lower corner one. Imagine in the early summer, you sit in the pavilion. In front of you is a large lake with several boats on it. You can see a stone bridge and several willow trees shaking its branches slightly. Outside is the soft and misty rain dropped on the lake. It is the only sound you can hear. You can think anything or nothing, just like the people thousands years ago. I can not find a second place, without religion, but can purify your heart.

    The top one and left lower corner one are not part of Jiangnan. The top one is  an old north city. The left one is an old town where minority lives. (Click the dolphin to open the poem, and click the poem to hide it.)