Jun 20, 2014

Given \(N\) denominations,how can a given amount of money \(V\) be made with the least number of coins? The most intuitive solution is greedy algorithm: sort the denominations, try the largest denominations lower than the value every time, and decrease the value with the denominations picked in every iteration. Repeat this process until the value reduces to 0. This greedy strategy works for the US (and most other) coin systems, However, it is not a general solution to all denomincations. For example, if the coin denominations were 1, 3 and 4, then to make 6, the greedy algorithm would choose three coins (4,1,1) whereas the optimal solution is two coins (3,3).

Jun 18, 2014

The Problem:

Jun 17, 2014

Problem:

Jun 14, 2014

The objective of Soduku game is to fill a \(9 \times 9\) grid with digits so that each column, each row, and each of the nine \(3 \times 3\) sub-grids that compose the grid (also called “boxes”, “blocks”, “regions”, or “sub-squares”) contains all of the digits from 1 to 9. A solved Soduku game is like:

Jun 12, 2014

According to LeetCode:

May 26, 2014

This is the first article on binary tree operations. For other topics on binary tree, please refer to:

Apr 30, 2014

This is a summary of doing human action recognition using Fisher Vector with (Improved) Dense Trjectory Features(DTF) and STIP features on UCF 101 dataset(http://crcv.ucf.edu/data/UCF101.php). In the STIP features, two low-level visual features HOG and HOF are integrated, with dimensions 72 and 90 respectively. The (improved) DTF employ more features(TR, HOG, HOF and MBHx/MBHy) with longer dimensions.

Apr 18, 2014

1. Inclusion Property
2. Code Change
3. Experiments
4. Conclusion

Mar 29, 2014

1. Procedure of installing Jekyll in Mac OS X

Mar 26, 2014

Printing Pascal Triangle seems like an easy problem, however, it is not that easy to print a good-looking Pascal Triangle.

To print the Pascal Triangle, for each line, first print spaces to the left of numbers, and then print digit numbers.

To calculate Pascal numbers, two assays can be used: one array to store numbers of above line, the other array to store numbers of this line. The first line has 1 number(1), the second lien has 2 numbers(1 1), the third line has three numbers(1 2 1) and so on.

To make the Pascal Triangle more readable, print spaces between two neighbor  numbers in the same line.

// Pascal triangle
#include <iostream>
#include <iomanip>
#include <cstring>
using namespace std;

const int WIDTH=7;
int main()
{
	int* oldarr=new int[WIDTH]; // store numbers of above row
	int* newarr=new int[WIDTH]; // store numbers of current row

	for(int i=0;i<WIDTH;++i) // cntrol row counting
	{
		for(int j=0;j<WIDTH-i-1;++j) // left space
			cout << setw(2) << " ";

		// set default boundary numbers
		newarr[0]=1;
		if(i<=1)
			newarr[i]=1;

		if(i<=2)
		{
			for(int k=1;k<i;++k)
				newarr[k]=oldarr[k-1]+oldarr[k];
		}
		memcpy(oldarr,newarr,sizeof(int)*WIDTH);

		// Print the middle part
		int idx=0;
		int flag=(WIDTH-i-1)%2;
		for(int j=WIDTH-i-1;j<WIDTH+i;++j)
		{
			if(j%2==flag)
			{
				cout << setw(2) << newarr[idx++];
			} else {
				cout << setw(2) << " ";
			}
		}
		
		//for(int j=WIDTH+i;j&lt;WIDTH;++j) // Print right space, if you like
		//	cout&lt;&lt;setw(4)&lt;&lt;&quot; &quot;;

		cout << endl;
	}

	delete [] oldarr;
	delete [] newarr;

	return 0;
}

The output looks like:

             1
           1   1
         1   2   1
       1   3   3   1
     1   4   6   4   1
   1   5  10  10   5   1
 1   6  15  20  15   6   1